Loading...
Note: File does not exist in v6.2.
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5
6*/
7#include <linux/export.h>
8#include <linux/extable.h>
9#include <linux/moduleloader.h>
10#include <linux/module_signature.h>
11#include <linux/trace_events.h>
12#include <linux/init.h>
13#include <linux/kallsyms.h>
14#include <linux/file.h>
15#include <linux/fs.h>
16#include <linux/sysfs.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19#include <linux/vmalloc.h>
20#include <linux/elf.h>
21#include <linux/proc_fs.h>
22#include <linux/security.h>
23#include <linux/seq_file.h>
24#include <linux/syscalls.h>
25#include <linux/fcntl.h>
26#include <linux/rcupdate.h>
27#include <linux/capability.h>
28#include <linux/cpu.h>
29#include <linux/moduleparam.h>
30#include <linux/errno.h>
31#include <linux/err.h>
32#include <linux/vermagic.h>
33#include <linux/notifier.h>
34#include <linux/sched.h>
35#include <linux/device.h>
36#include <linux/string.h>
37#include <linux/mutex.h>
38#include <linux/rculist.h>
39#include <linux/uaccess.h>
40#include <asm/cacheflush.h>
41#include <linux/set_memory.h>
42#include <asm/mmu_context.h>
43#include <linux/license.h>
44#include <asm/sections.h>
45#include <linux/tracepoint.h>
46#include <linux/ftrace.h>
47#include <linux/livepatch.h>
48#include <linux/async.h>
49#include <linux/percpu.h>
50#include <linux/kmemleak.h>
51#include <linux/jump_label.h>
52#include <linux/pfn.h>
53#include <linux/bsearch.h>
54#include <linux/dynamic_debug.h>
55#include <linux/audit.h>
56#include <uapi/linux/module.h>
57#include "module-internal.h"
58
59#define CREATE_TRACE_POINTS
60#include <trace/events/module.h>
61
62#ifndef ARCH_SHF_SMALL
63#define ARCH_SHF_SMALL 0
64#endif
65
66/*
67 * Modules' sections will be aligned on page boundaries
68 * to ensure complete separation of code and data, but
69 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
70 */
71#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
72# define debug_align(X) ALIGN(X, PAGE_SIZE)
73#else
74# define debug_align(X) (X)
75#endif
76
77/* If this is set, the section belongs in the init part of the module */
78#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
79
80/*
81 * Mutex protects:
82 * 1) List of modules (also safely readable with preempt_disable),
83 * 2) module_use links,
84 * 3) module_addr_min/module_addr_max.
85 * (delete and add uses RCU list operations). */
86DEFINE_MUTEX(module_mutex);
87EXPORT_SYMBOL_GPL(module_mutex);
88static LIST_HEAD(modules);
89
90/* Work queue for freeing init sections in success case */
91static struct work_struct init_free_wq;
92static struct llist_head init_free_list;
93
94#ifdef CONFIG_MODULES_TREE_LOOKUP
95
96/*
97 * Use a latched RB-tree for __module_address(); this allows us to use
98 * RCU-sched lookups of the address from any context.
99 *
100 * This is conditional on PERF_EVENTS || TRACING because those can really hit
101 * __module_address() hard by doing a lot of stack unwinding; potentially from
102 * NMI context.
103 */
104
105static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
106{
107 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
108
109 return (unsigned long)layout->base;
110}
111
112static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
113{
114 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
115
116 return (unsigned long)layout->size;
117}
118
119static __always_inline bool
120mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
121{
122 return __mod_tree_val(a) < __mod_tree_val(b);
123}
124
125static __always_inline int
126mod_tree_comp(void *key, struct latch_tree_node *n)
127{
128 unsigned long val = (unsigned long)key;
129 unsigned long start, end;
130
131 start = __mod_tree_val(n);
132 if (val < start)
133 return -1;
134
135 end = start + __mod_tree_size(n);
136 if (val >= end)
137 return 1;
138
139 return 0;
140}
141
142static const struct latch_tree_ops mod_tree_ops = {
143 .less = mod_tree_less,
144 .comp = mod_tree_comp,
145};
146
147static struct mod_tree_root {
148 struct latch_tree_root root;
149 unsigned long addr_min;
150 unsigned long addr_max;
151} mod_tree __cacheline_aligned = {
152 .addr_min = -1UL,
153};
154
155#define module_addr_min mod_tree.addr_min
156#define module_addr_max mod_tree.addr_max
157
158static noinline void __mod_tree_insert(struct mod_tree_node *node)
159{
160 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
161}
162
163static void __mod_tree_remove(struct mod_tree_node *node)
164{
165 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
166}
167
168/*
169 * These modifications: insert, remove_init and remove; are serialized by the
170 * module_mutex.
171 */
172static void mod_tree_insert(struct module *mod)
173{
174 mod->core_layout.mtn.mod = mod;
175 mod->init_layout.mtn.mod = mod;
176
177 __mod_tree_insert(&mod->core_layout.mtn);
178 if (mod->init_layout.size)
179 __mod_tree_insert(&mod->init_layout.mtn);
180}
181
182static void mod_tree_remove_init(struct module *mod)
183{
184 if (mod->init_layout.size)
185 __mod_tree_remove(&mod->init_layout.mtn);
186}
187
188static void mod_tree_remove(struct module *mod)
189{
190 __mod_tree_remove(&mod->core_layout.mtn);
191 mod_tree_remove_init(mod);
192}
193
194static struct module *mod_find(unsigned long addr)
195{
196 struct latch_tree_node *ltn;
197
198 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
199 if (!ltn)
200 return NULL;
201
202 return container_of(ltn, struct mod_tree_node, node)->mod;
203}
204
205#else /* MODULES_TREE_LOOKUP */
206
207static unsigned long module_addr_min = -1UL, module_addr_max = 0;
208
209static void mod_tree_insert(struct module *mod) { }
210static void mod_tree_remove_init(struct module *mod) { }
211static void mod_tree_remove(struct module *mod) { }
212
213static struct module *mod_find(unsigned long addr)
214{
215 struct module *mod;
216
217 list_for_each_entry_rcu(mod, &modules, list) {
218 if (within_module(addr, mod))
219 return mod;
220 }
221
222 return NULL;
223}
224
225#endif /* MODULES_TREE_LOOKUP */
226
227/*
228 * Bounds of module text, for speeding up __module_address.
229 * Protected by module_mutex.
230 */
231static void __mod_update_bounds(void *base, unsigned int size)
232{
233 unsigned long min = (unsigned long)base;
234 unsigned long max = min + size;
235
236 if (min < module_addr_min)
237 module_addr_min = min;
238 if (max > module_addr_max)
239 module_addr_max = max;
240}
241
242static void mod_update_bounds(struct module *mod)
243{
244 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
245 if (mod->init_layout.size)
246 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
247}
248
249#ifdef CONFIG_KGDB_KDB
250struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
251#endif /* CONFIG_KGDB_KDB */
252
253static void module_assert_mutex(void)
254{
255 lockdep_assert_held(&module_mutex);
256}
257
258static void module_assert_mutex_or_preempt(void)
259{
260#ifdef CONFIG_LOCKDEP
261 if (unlikely(!debug_locks))
262 return;
263
264 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
265 !lockdep_is_held(&module_mutex));
266#endif
267}
268
269static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
270module_param(sig_enforce, bool_enable_only, 0644);
271
272/*
273 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
274 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
275 */
276bool is_module_sig_enforced(void)
277{
278 return sig_enforce;
279}
280EXPORT_SYMBOL(is_module_sig_enforced);
281
282void set_module_sig_enforced(void)
283{
284 sig_enforce = true;
285}
286
287/* Block module loading/unloading? */
288int modules_disabled = 0;
289core_param(nomodule, modules_disabled, bint, 0);
290
291/* Waiting for a module to finish initializing? */
292static DECLARE_WAIT_QUEUE_HEAD(module_wq);
293
294static BLOCKING_NOTIFIER_HEAD(module_notify_list);
295
296int register_module_notifier(struct notifier_block *nb)
297{
298 return blocking_notifier_chain_register(&module_notify_list, nb);
299}
300EXPORT_SYMBOL(register_module_notifier);
301
302int unregister_module_notifier(struct notifier_block *nb)
303{
304 return blocking_notifier_chain_unregister(&module_notify_list, nb);
305}
306EXPORT_SYMBOL(unregister_module_notifier);
307
308/*
309 * We require a truly strong try_module_get(): 0 means success.
310 * Otherwise an error is returned due to ongoing or failed
311 * initialization etc.
312 */
313static inline int strong_try_module_get(struct module *mod)
314{
315 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
316 if (mod && mod->state == MODULE_STATE_COMING)
317 return -EBUSY;
318 if (try_module_get(mod))
319 return 0;
320 else
321 return -ENOENT;
322}
323
324static inline void add_taint_module(struct module *mod, unsigned flag,
325 enum lockdep_ok lockdep_ok)
326{
327 add_taint(flag, lockdep_ok);
328 set_bit(flag, &mod->taints);
329}
330
331/*
332 * A thread that wants to hold a reference to a module only while it
333 * is running can call this to safely exit. nfsd and lockd use this.
334 */
335void __noreturn __module_put_and_exit(struct module *mod, long code)
336{
337 module_put(mod);
338 do_exit(code);
339}
340EXPORT_SYMBOL(__module_put_and_exit);
341
342/* Find a module section: 0 means not found. */
343static unsigned int find_sec(const struct load_info *info, const char *name)
344{
345 unsigned int i;
346
347 for (i = 1; i < info->hdr->e_shnum; i++) {
348 Elf_Shdr *shdr = &info->sechdrs[i];
349 /* Alloc bit cleared means "ignore it." */
350 if ((shdr->sh_flags & SHF_ALLOC)
351 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
352 return i;
353 }
354 return 0;
355}
356
357/* Find a module section, or NULL. */
358static void *section_addr(const struct load_info *info, const char *name)
359{
360 /* Section 0 has sh_addr 0. */
361 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
362}
363
364/* Find a module section, or NULL. Fill in number of "objects" in section. */
365static void *section_objs(const struct load_info *info,
366 const char *name,
367 size_t object_size,
368 unsigned int *num)
369{
370 unsigned int sec = find_sec(info, name);
371
372 /* Section 0 has sh_addr 0 and sh_size 0. */
373 *num = info->sechdrs[sec].sh_size / object_size;
374 return (void *)info->sechdrs[sec].sh_addr;
375}
376
377/* Provided by the linker */
378extern const struct kernel_symbol __start___ksymtab[];
379extern const struct kernel_symbol __stop___ksymtab[];
380extern const struct kernel_symbol __start___ksymtab_gpl[];
381extern const struct kernel_symbol __stop___ksymtab_gpl[];
382extern const struct kernel_symbol __start___ksymtab_gpl_future[];
383extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
384extern const s32 __start___kcrctab[];
385extern const s32 __start___kcrctab_gpl[];
386extern const s32 __start___kcrctab_gpl_future[];
387#ifdef CONFIG_UNUSED_SYMBOLS
388extern const struct kernel_symbol __start___ksymtab_unused[];
389extern const struct kernel_symbol __stop___ksymtab_unused[];
390extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
391extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
392extern const s32 __start___kcrctab_unused[];
393extern const s32 __start___kcrctab_unused_gpl[];
394#endif
395
396#ifndef CONFIG_MODVERSIONS
397#define symversion(base, idx) NULL
398#else
399#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
400#endif
401
402static bool each_symbol_in_section(const struct symsearch *arr,
403 unsigned int arrsize,
404 struct module *owner,
405 bool (*fn)(const struct symsearch *syms,
406 struct module *owner,
407 void *data),
408 void *data)
409{
410 unsigned int j;
411
412 for (j = 0; j < arrsize; j++) {
413 if (fn(&arr[j], owner, data))
414 return true;
415 }
416
417 return false;
418}
419
420/* Returns true as soon as fn returns true, otherwise false. */
421bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
422 struct module *owner,
423 void *data),
424 void *data)
425{
426 struct module *mod;
427 static const struct symsearch arr[] = {
428 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
429 NOT_GPL_ONLY, false },
430 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
431 __start___kcrctab_gpl,
432 GPL_ONLY, false },
433 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
434 __start___kcrctab_gpl_future,
435 WILL_BE_GPL_ONLY, false },
436#ifdef CONFIG_UNUSED_SYMBOLS
437 { __start___ksymtab_unused, __stop___ksymtab_unused,
438 __start___kcrctab_unused,
439 NOT_GPL_ONLY, true },
440 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
441 __start___kcrctab_unused_gpl,
442 GPL_ONLY, true },
443#endif
444 };
445
446 module_assert_mutex_or_preempt();
447
448 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
449 return true;
450
451 list_for_each_entry_rcu(mod, &modules, list) {
452 struct symsearch arr[] = {
453 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
454 NOT_GPL_ONLY, false },
455 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
456 mod->gpl_crcs,
457 GPL_ONLY, false },
458 { mod->gpl_future_syms,
459 mod->gpl_future_syms + mod->num_gpl_future_syms,
460 mod->gpl_future_crcs,
461 WILL_BE_GPL_ONLY, false },
462#ifdef CONFIG_UNUSED_SYMBOLS
463 { mod->unused_syms,
464 mod->unused_syms + mod->num_unused_syms,
465 mod->unused_crcs,
466 NOT_GPL_ONLY, true },
467 { mod->unused_gpl_syms,
468 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
469 mod->unused_gpl_crcs,
470 GPL_ONLY, true },
471#endif
472 };
473
474 if (mod->state == MODULE_STATE_UNFORMED)
475 continue;
476
477 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
478 return true;
479 }
480 return false;
481}
482EXPORT_SYMBOL_GPL(each_symbol_section);
483
484struct find_symbol_arg {
485 /* Input */
486 const char *name;
487 bool gplok;
488 bool warn;
489
490 /* Output */
491 struct module *owner;
492 const s32 *crc;
493 const struct kernel_symbol *sym;
494};
495
496static bool check_exported_symbol(const struct symsearch *syms,
497 struct module *owner,
498 unsigned int symnum, void *data)
499{
500 struct find_symbol_arg *fsa = data;
501
502 if (!fsa->gplok) {
503 if (syms->licence == GPL_ONLY)
504 return false;
505 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
506 pr_warn("Symbol %s is being used by a non-GPL module, "
507 "which will not be allowed in the future\n",
508 fsa->name);
509 }
510 }
511
512#ifdef CONFIG_UNUSED_SYMBOLS
513 if (syms->unused && fsa->warn) {
514 pr_warn("Symbol %s is marked as UNUSED, however this module is "
515 "using it.\n", fsa->name);
516 pr_warn("This symbol will go away in the future.\n");
517 pr_warn("Please evaluate if this is the right api to use and "
518 "if it really is, submit a report to the linux kernel "
519 "mailing list together with submitting your code for "
520 "inclusion.\n");
521 }
522#endif
523
524 fsa->owner = owner;
525 fsa->crc = symversion(syms->crcs, symnum);
526 fsa->sym = &syms->start[symnum];
527 return true;
528}
529
530static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
531{
532#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
533 return (unsigned long)offset_to_ptr(&sym->value_offset);
534#else
535 return sym->value;
536#endif
537}
538
539static const char *kernel_symbol_name(const struct kernel_symbol *sym)
540{
541#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
542 return offset_to_ptr(&sym->name_offset);
543#else
544 return sym->name;
545#endif
546}
547
548static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
549{
550#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
551 if (!sym->namespace_offset)
552 return NULL;
553 return offset_to_ptr(&sym->namespace_offset);
554#else
555 return sym->namespace;
556#endif
557}
558
559static int cmp_name(const void *name, const void *sym)
560{
561 return strcmp(name, kernel_symbol_name(sym));
562}
563
564static bool find_exported_symbol_in_section(const struct symsearch *syms,
565 struct module *owner,
566 void *data)
567{
568 struct find_symbol_arg *fsa = data;
569 struct kernel_symbol *sym;
570
571 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
572 sizeof(struct kernel_symbol), cmp_name);
573
574 if (sym != NULL && check_exported_symbol(syms, owner,
575 sym - syms->start, data))
576 return true;
577
578 return false;
579}
580
581/* Find an exported symbol and return it, along with, (optional) crc and
582 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
583const struct kernel_symbol *find_symbol(const char *name,
584 struct module **owner,
585 const s32 **crc,
586 bool gplok,
587 bool warn)
588{
589 struct find_symbol_arg fsa;
590
591 fsa.name = name;
592 fsa.gplok = gplok;
593 fsa.warn = warn;
594
595 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
596 if (owner)
597 *owner = fsa.owner;
598 if (crc)
599 *crc = fsa.crc;
600 return fsa.sym;
601 }
602
603 pr_debug("Failed to find symbol %s\n", name);
604 return NULL;
605}
606EXPORT_SYMBOL_GPL(find_symbol);
607
608/*
609 * Search for module by name: must hold module_mutex (or preempt disabled
610 * for read-only access).
611 */
612static struct module *find_module_all(const char *name, size_t len,
613 bool even_unformed)
614{
615 struct module *mod;
616
617 module_assert_mutex_or_preempt();
618
619 list_for_each_entry_rcu(mod, &modules, list) {
620 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
621 continue;
622 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
623 return mod;
624 }
625 return NULL;
626}
627
628struct module *find_module(const char *name)
629{
630 module_assert_mutex();
631 return find_module_all(name, strlen(name), false);
632}
633EXPORT_SYMBOL_GPL(find_module);
634
635#ifdef CONFIG_SMP
636
637static inline void __percpu *mod_percpu(struct module *mod)
638{
639 return mod->percpu;
640}
641
642static int percpu_modalloc(struct module *mod, struct load_info *info)
643{
644 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
645 unsigned long align = pcpusec->sh_addralign;
646
647 if (!pcpusec->sh_size)
648 return 0;
649
650 if (align > PAGE_SIZE) {
651 pr_warn("%s: per-cpu alignment %li > %li\n",
652 mod->name, align, PAGE_SIZE);
653 align = PAGE_SIZE;
654 }
655
656 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
657 if (!mod->percpu) {
658 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
659 mod->name, (unsigned long)pcpusec->sh_size);
660 return -ENOMEM;
661 }
662 mod->percpu_size = pcpusec->sh_size;
663 return 0;
664}
665
666static void percpu_modfree(struct module *mod)
667{
668 free_percpu(mod->percpu);
669}
670
671static unsigned int find_pcpusec(struct load_info *info)
672{
673 return find_sec(info, ".data..percpu");
674}
675
676static void percpu_modcopy(struct module *mod,
677 const void *from, unsigned long size)
678{
679 int cpu;
680
681 for_each_possible_cpu(cpu)
682 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
683}
684
685bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
686{
687 struct module *mod;
688 unsigned int cpu;
689
690 preempt_disable();
691
692 list_for_each_entry_rcu(mod, &modules, list) {
693 if (mod->state == MODULE_STATE_UNFORMED)
694 continue;
695 if (!mod->percpu_size)
696 continue;
697 for_each_possible_cpu(cpu) {
698 void *start = per_cpu_ptr(mod->percpu, cpu);
699 void *va = (void *)addr;
700
701 if (va >= start && va < start + mod->percpu_size) {
702 if (can_addr) {
703 *can_addr = (unsigned long) (va - start);
704 *can_addr += (unsigned long)
705 per_cpu_ptr(mod->percpu,
706 get_boot_cpu_id());
707 }
708 preempt_enable();
709 return true;
710 }
711 }
712 }
713
714 preempt_enable();
715 return false;
716}
717
718/**
719 * is_module_percpu_address - test whether address is from module static percpu
720 * @addr: address to test
721 *
722 * Test whether @addr belongs to module static percpu area.
723 *
724 * RETURNS:
725 * %true if @addr is from module static percpu area
726 */
727bool is_module_percpu_address(unsigned long addr)
728{
729 return __is_module_percpu_address(addr, NULL);
730}
731
732#else /* ... !CONFIG_SMP */
733
734static inline void __percpu *mod_percpu(struct module *mod)
735{
736 return NULL;
737}
738static int percpu_modalloc(struct module *mod, struct load_info *info)
739{
740 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
741 if (info->sechdrs[info->index.pcpu].sh_size != 0)
742 return -ENOMEM;
743 return 0;
744}
745static inline void percpu_modfree(struct module *mod)
746{
747}
748static unsigned int find_pcpusec(struct load_info *info)
749{
750 return 0;
751}
752static inline void percpu_modcopy(struct module *mod,
753 const void *from, unsigned long size)
754{
755 /* pcpusec should be 0, and size of that section should be 0. */
756 BUG_ON(size != 0);
757}
758bool is_module_percpu_address(unsigned long addr)
759{
760 return false;
761}
762
763bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
764{
765 return false;
766}
767
768#endif /* CONFIG_SMP */
769
770#define MODINFO_ATTR(field) \
771static void setup_modinfo_##field(struct module *mod, const char *s) \
772{ \
773 mod->field = kstrdup(s, GFP_KERNEL); \
774} \
775static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
776 struct module_kobject *mk, char *buffer) \
777{ \
778 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
779} \
780static int modinfo_##field##_exists(struct module *mod) \
781{ \
782 return mod->field != NULL; \
783} \
784static void free_modinfo_##field(struct module *mod) \
785{ \
786 kfree(mod->field); \
787 mod->field = NULL; \
788} \
789static struct module_attribute modinfo_##field = { \
790 .attr = { .name = __stringify(field), .mode = 0444 }, \
791 .show = show_modinfo_##field, \
792 .setup = setup_modinfo_##field, \
793 .test = modinfo_##field##_exists, \
794 .free = free_modinfo_##field, \
795};
796
797MODINFO_ATTR(version);
798MODINFO_ATTR(srcversion);
799
800static char last_unloaded_module[MODULE_NAME_LEN+1];
801
802#ifdef CONFIG_MODULE_UNLOAD
803
804EXPORT_TRACEPOINT_SYMBOL(module_get);
805
806/* MODULE_REF_BASE is the base reference count by kmodule loader. */
807#define MODULE_REF_BASE 1
808
809/* Init the unload section of the module. */
810static int module_unload_init(struct module *mod)
811{
812 /*
813 * Initialize reference counter to MODULE_REF_BASE.
814 * refcnt == 0 means module is going.
815 */
816 atomic_set(&mod->refcnt, MODULE_REF_BASE);
817
818 INIT_LIST_HEAD(&mod->source_list);
819 INIT_LIST_HEAD(&mod->target_list);
820
821 /* Hold reference count during initialization. */
822 atomic_inc(&mod->refcnt);
823
824 return 0;
825}
826
827/* Does a already use b? */
828static int already_uses(struct module *a, struct module *b)
829{
830 struct module_use *use;
831
832 list_for_each_entry(use, &b->source_list, source_list) {
833 if (use->source == a) {
834 pr_debug("%s uses %s!\n", a->name, b->name);
835 return 1;
836 }
837 }
838 pr_debug("%s does not use %s!\n", a->name, b->name);
839 return 0;
840}
841
842/*
843 * Module a uses b
844 * - we add 'a' as a "source", 'b' as a "target" of module use
845 * - the module_use is added to the list of 'b' sources (so
846 * 'b' can walk the list to see who sourced them), and of 'a'
847 * targets (so 'a' can see what modules it targets).
848 */
849static int add_module_usage(struct module *a, struct module *b)
850{
851 struct module_use *use;
852
853 pr_debug("Allocating new usage for %s.\n", a->name);
854 use = kmalloc(sizeof(*use), GFP_ATOMIC);
855 if (!use)
856 return -ENOMEM;
857
858 use->source = a;
859 use->target = b;
860 list_add(&use->source_list, &b->source_list);
861 list_add(&use->target_list, &a->target_list);
862 return 0;
863}
864
865/* Module a uses b: caller needs module_mutex() */
866int ref_module(struct module *a, struct module *b)
867{
868 int err;
869
870 if (b == NULL || already_uses(a, b))
871 return 0;
872
873 /* If module isn't available, we fail. */
874 err = strong_try_module_get(b);
875 if (err)
876 return err;
877
878 err = add_module_usage(a, b);
879 if (err) {
880 module_put(b);
881 return err;
882 }
883 return 0;
884}
885EXPORT_SYMBOL_GPL(ref_module);
886
887/* Clear the unload stuff of the module. */
888static void module_unload_free(struct module *mod)
889{
890 struct module_use *use, *tmp;
891
892 mutex_lock(&module_mutex);
893 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
894 struct module *i = use->target;
895 pr_debug("%s unusing %s\n", mod->name, i->name);
896 module_put(i);
897 list_del(&use->source_list);
898 list_del(&use->target_list);
899 kfree(use);
900 }
901 mutex_unlock(&module_mutex);
902}
903
904#ifdef CONFIG_MODULE_FORCE_UNLOAD
905static inline int try_force_unload(unsigned int flags)
906{
907 int ret = (flags & O_TRUNC);
908 if (ret)
909 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
910 return ret;
911}
912#else
913static inline int try_force_unload(unsigned int flags)
914{
915 return 0;
916}
917#endif /* CONFIG_MODULE_FORCE_UNLOAD */
918
919/* Try to release refcount of module, 0 means success. */
920static int try_release_module_ref(struct module *mod)
921{
922 int ret;
923
924 /* Try to decrement refcnt which we set at loading */
925 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
926 BUG_ON(ret < 0);
927 if (ret)
928 /* Someone can put this right now, recover with checking */
929 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
930
931 return ret;
932}
933
934static int try_stop_module(struct module *mod, int flags, int *forced)
935{
936 /* If it's not unused, quit unless we're forcing. */
937 if (try_release_module_ref(mod) != 0) {
938 *forced = try_force_unload(flags);
939 if (!(*forced))
940 return -EWOULDBLOCK;
941 }
942
943 /* Mark it as dying. */
944 mod->state = MODULE_STATE_GOING;
945
946 return 0;
947}
948
949/**
950 * module_refcount - return the refcount or -1 if unloading
951 *
952 * @mod: the module we're checking
953 *
954 * Returns:
955 * -1 if the module is in the process of unloading
956 * otherwise the number of references in the kernel to the module
957 */
958int module_refcount(struct module *mod)
959{
960 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
961}
962EXPORT_SYMBOL(module_refcount);
963
964/* This exists whether we can unload or not */
965static void free_module(struct module *mod);
966
967SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
968 unsigned int, flags)
969{
970 struct module *mod;
971 char name[MODULE_NAME_LEN];
972 int ret, forced = 0;
973
974 if (!capable(CAP_SYS_MODULE) || modules_disabled)
975 return -EPERM;
976
977 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
978 return -EFAULT;
979 name[MODULE_NAME_LEN-1] = '\0';
980
981 audit_log_kern_module(name);
982
983 if (mutex_lock_interruptible(&module_mutex) != 0)
984 return -EINTR;
985
986 mod = find_module(name);
987 if (!mod) {
988 ret = -ENOENT;
989 goto out;
990 }
991
992 if (!list_empty(&mod->source_list)) {
993 /* Other modules depend on us: get rid of them first. */
994 ret = -EWOULDBLOCK;
995 goto out;
996 }
997
998 /* Doing init or already dying? */
999 if (mod->state != MODULE_STATE_LIVE) {
1000 /* FIXME: if (force), slam module count damn the torpedoes */
1001 pr_debug("%s already dying\n", mod->name);
1002 ret = -EBUSY;
1003 goto out;
1004 }
1005
1006 /* If it has an init func, it must have an exit func to unload */
1007 if (mod->init && !mod->exit) {
1008 forced = try_force_unload(flags);
1009 if (!forced) {
1010 /* This module can't be removed */
1011 ret = -EBUSY;
1012 goto out;
1013 }
1014 }
1015
1016 /* Stop the machine so refcounts can't move and disable module. */
1017 ret = try_stop_module(mod, flags, &forced);
1018 if (ret != 0)
1019 goto out;
1020
1021 mutex_unlock(&module_mutex);
1022 /* Final destruction now no one is using it. */
1023 if (mod->exit != NULL)
1024 mod->exit();
1025 blocking_notifier_call_chain(&module_notify_list,
1026 MODULE_STATE_GOING, mod);
1027 klp_module_going(mod);
1028 ftrace_release_mod(mod);
1029
1030 async_synchronize_full();
1031
1032 /* Store the name of the last unloaded module for diagnostic purposes */
1033 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1034
1035 free_module(mod);
1036 return 0;
1037out:
1038 mutex_unlock(&module_mutex);
1039 return ret;
1040}
1041
1042static inline void print_unload_info(struct seq_file *m, struct module *mod)
1043{
1044 struct module_use *use;
1045 int printed_something = 0;
1046
1047 seq_printf(m, " %i ", module_refcount(mod));
1048
1049 /*
1050 * Always include a trailing , so userspace can differentiate
1051 * between this and the old multi-field proc format.
1052 */
1053 list_for_each_entry(use, &mod->source_list, source_list) {
1054 printed_something = 1;
1055 seq_printf(m, "%s,", use->source->name);
1056 }
1057
1058 if (mod->init != NULL && mod->exit == NULL) {
1059 printed_something = 1;
1060 seq_puts(m, "[permanent],");
1061 }
1062
1063 if (!printed_something)
1064 seq_puts(m, "-");
1065}
1066
1067void __symbol_put(const char *symbol)
1068{
1069 struct module *owner;
1070
1071 preempt_disable();
1072 if (!find_symbol(symbol, &owner, NULL, true, false))
1073 BUG();
1074 module_put(owner);
1075 preempt_enable();
1076}
1077EXPORT_SYMBOL(__symbol_put);
1078
1079/* Note this assumes addr is a function, which it currently always is. */
1080void symbol_put_addr(void *addr)
1081{
1082 struct module *modaddr;
1083 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1084
1085 if (core_kernel_text(a))
1086 return;
1087
1088 /*
1089 * Even though we hold a reference on the module; we still need to
1090 * disable preemption in order to safely traverse the data structure.
1091 */
1092 preempt_disable();
1093 modaddr = __module_text_address(a);
1094 BUG_ON(!modaddr);
1095 module_put(modaddr);
1096 preempt_enable();
1097}
1098EXPORT_SYMBOL_GPL(symbol_put_addr);
1099
1100static ssize_t show_refcnt(struct module_attribute *mattr,
1101 struct module_kobject *mk, char *buffer)
1102{
1103 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1104}
1105
1106static struct module_attribute modinfo_refcnt =
1107 __ATTR(refcnt, 0444, show_refcnt, NULL);
1108
1109void __module_get(struct module *module)
1110{
1111 if (module) {
1112 preempt_disable();
1113 atomic_inc(&module->refcnt);
1114 trace_module_get(module, _RET_IP_);
1115 preempt_enable();
1116 }
1117}
1118EXPORT_SYMBOL(__module_get);
1119
1120bool try_module_get(struct module *module)
1121{
1122 bool ret = true;
1123
1124 if (module) {
1125 preempt_disable();
1126 /* Note: here, we can fail to get a reference */
1127 if (likely(module_is_live(module) &&
1128 atomic_inc_not_zero(&module->refcnt) != 0))
1129 trace_module_get(module, _RET_IP_);
1130 else
1131 ret = false;
1132
1133 preempt_enable();
1134 }
1135 return ret;
1136}
1137EXPORT_SYMBOL(try_module_get);
1138
1139void module_put(struct module *module)
1140{
1141 int ret;
1142
1143 if (module) {
1144 preempt_disable();
1145 ret = atomic_dec_if_positive(&module->refcnt);
1146 WARN_ON(ret < 0); /* Failed to put refcount */
1147 trace_module_put(module, _RET_IP_);
1148 preempt_enable();
1149 }
1150}
1151EXPORT_SYMBOL(module_put);
1152
1153#else /* !CONFIG_MODULE_UNLOAD */
1154static inline void print_unload_info(struct seq_file *m, struct module *mod)
1155{
1156 /* We don't know the usage count, or what modules are using. */
1157 seq_puts(m, " - -");
1158}
1159
1160static inline void module_unload_free(struct module *mod)
1161{
1162}
1163
1164int ref_module(struct module *a, struct module *b)
1165{
1166 return strong_try_module_get(b);
1167}
1168EXPORT_SYMBOL_GPL(ref_module);
1169
1170static inline int module_unload_init(struct module *mod)
1171{
1172 return 0;
1173}
1174#endif /* CONFIG_MODULE_UNLOAD */
1175
1176static size_t module_flags_taint(struct module *mod, char *buf)
1177{
1178 size_t l = 0;
1179 int i;
1180
1181 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1182 if (taint_flags[i].module && test_bit(i, &mod->taints))
1183 buf[l++] = taint_flags[i].c_true;
1184 }
1185
1186 return l;
1187}
1188
1189static ssize_t show_initstate(struct module_attribute *mattr,
1190 struct module_kobject *mk, char *buffer)
1191{
1192 const char *state = "unknown";
1193
1194 switch (mk->mod->state) {
1195 case MODULE_STATE_LIVE:
1196 state = "live";
1197 break;
1198 case MODULE_STATE_COMING:
1199 state = "coming";
1200 break;
1201 case MODULE_STATE_GOING:
1202 state = "going";
1203 break;
1204 default:
1205 BUG();
1206 }
1207 return sprintf(buffer, "%s\n", state);
1208}
1209
1210static struct module_attribute modinfo_initstate =
1211 __ATTR(initstate, 0444, show_initstate, NULL);
1212
1213static ssize_t store_uevent(struct module_attribute *mattr,
1214 struct module_kobject *mk,
1215 const char *buffer, size_t count)
1216{
1217 int rc;
1218
1219 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1220 return rc ? rc : count;
1221}
1222
1223struct module_attribute module_uevent =
1224 __ATTR(uevent, 0200, NULL, store_uevent);
1225
1226static ssize_t show_coresize(struct module_attribute *mattr,
1227 struct module_kobject *mk, char *buffer)
1228{
1229 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1230}
1231
1232static struct module_attribute modinfo_coresize =
1233 __ATTR(coresize, 0444, show_coresize, NULL);
1234
1235static ssize_t show_initsize(struct module_attribute *mattr,
1236 struct module_kobject *mk, char *buffer)
1237{
1238 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1239}
1240
1241static struct module_attribute modinfo_initsize =
1242 __ATTR(initsize, 0444, show_initsize, NULL);
1243
1244static ssize_t show_taint(struct module_attribute *mattr,
1245 struct module_kobject *mk, char *buffer)
1246{
1247 size_t l;
1248
1249 l = module_flags_taint(mk->mod, buffer);
1250 buffer[l++] = '\n';
1251 return l;
1252}
1253
1254static struct module_attribute modinfo_taint =
1255 __ATTR(taint, 0444, show_taint, NULL);
1256
1257static struct module_attribute *modinfo_attrs[] = {
1258 &module_uevent,
1259 &modinfo_version,
1260 &modinfo_srcversion,
1261 &modinfo_initstate,
1262 &modinfo_coresize,
1263 &modinfo_initsize,
1264 &modinfo_taint,
1265#ifdef CONFIG_MODULE_UNLOAD
1266 &modinfo_refcnt,
1267#endif
1268 NULL,
1269};
1270
1271static const char vermagic[] = VERMAGIC_STRING;
1272
1273static int try_to_force_load(struct module *mod, const char *reason)
1274{
1275#ifdef CONFIG_MODULE_FORCE_LOAD
1276 if (!test_taint(TAINT_FORCED_MODULE))
1277 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1278 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1279 return 0;
1280#else
1281 return -ENOEXEC;
1282#endif
1283}
1284
1285#ifdef CONFIG_MODVERSIONS
1286
1287static u32 resolve_rel_crc(const s32 *crc)
1288{
1289 return *(u32 *)((void *)crc + *crc);
1290}
1291
1292static int check_version(const struct load_info *info,
1293 const char *symname,
1294 struct module *mod,
1295 const s32 *crc)
1296{
1297 Elf_Shdr *sechdrs = info->sechdrs;
1298 unsigned int versindex = info->index.vers;
1299 unsigned int i, num_versions;
1300 struct modversion_info *versions;
1301
1302 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1303 if (!crc)
1304 return 1;
1305
1306 /* No versions at all? modprobe --force does this. */
1307 if (versindex == 0)
1308 return try_to_force_load(mod, symname) == 0;
1309
1310 versions = (void *) sechdrs[versindex].sh_addr;
1311 num_versions = sechdrs[versindex].sh_size
1312 / sizeof(struct modversion_info);
1313
1314 for (i = 0; i < num_versions; i++) {
1315 u32 crcval;
1316
1317 if (strcmp(versions[i].name, symname) != 0)
1318 continue;
1319
1320 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1321 crcval = resolve_rel_crc(crc);
1322 else
1323 crcval = *crc;
1324 if (versions[i].crc == crcval)
1325 return 1;
1326 pr_debug("Found checksum %X vs module %lX\n",
1327 crcval, versions[i].crc);
1328 goto bad_version;
1329 }
1330
1331 /* Broken toolchain. Warn once, then let it go.. */
1332 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1333 return 1;
1334
1335bad_version:
1336 pr_warn("%s: disagrees about version of symbol %s\n",
1337 info->name, symname);
1338 return 0;
1339}
1340
1341static inline int check_modstruct_version(const struct load_info *info,
1342 struct module *mod)
1343{
1344 const s32 *crc;
1345
1346 /*
1347 * Since this should be found in kernel (which can't be removed), no
1348 * locking is necessary -- use preempt_disable() to placate lockdep.
1349 */
1350 preempt_disable();
1351 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1352 preempt_enable();
1353 BUG();
1354 }
1355 preempt_enable();
1356 return check_version(info, "module_layout", mod, crc);
1357}
1358
1359/* First part is kernel version, which we ignore if module has crcs. */
1360static inline int same_magic(const char *amagic, const char *bmagic,
1361 bool has_crcs)
1362{
1363 if (has_crcs) {
1364 amagic += strcspn(amagic, " ");
1365 bmagic += strcspn(bmagic, " ");
1366 }
1367 return strcmp(amagic, bmagic) == 0;
1368}
1369#else
1370static inline int check_version(const struct load_info *info,
1371 const char *symname,
1372 struct module *mod,
1373 const s32 *crc)
1374{
1375 return 1;
1376}
1377
1378static inline int check_modstruct_version(const struct load_info *info,
1379 struct module *mod)
1380{
1381 return 1;
1382}
1383
1384static inline int same_magic(const char *amagic, const char *bmagic,
1385 bool has_crcs)
1386{
1387 return strcmp(amagic, bmagic) == 0;
1388}
1389#endif /* CONFIG_MODVERSIONS */
1390
1391static char *get_modinfo(const struct load_info *info, const char *tag);
1392static char *get_next_modinfo(const struct load_info *info, const char *tag,
1393 char *prev);
1394
1395static int verify_namespace_is_imported(const struct load_info *info,
1396 const struct kernel_symbol *sym,
1397 struct module *mod)
1398{
1399 const char *namespace;
1400 char *imported_namespace;
1401
1402 namespace = kernel_symbol_namespace(sym);
1403 if (namespace) {
1404 imported_namespace = get_modinfo(info, "import_ns");
1405 while (imported_namespace) {
1406 if (strcmp(namespace, imported_namespace) == 0)
1407 return 0;
1408 imported_namespace = get_next_modinfo(
1409 info, "import_ns", imported_namespace);
1410 }
1411#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1412 pr_warn(
1413#else
1414 pr_err(
1415#endif
1416 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1417 mod->name, kernel_symbol_name(sym), namespace);
1418#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1419 return -EINVAL;
1420#endif
1421 }
1422 return 0;
1423}
1424
1425
1426/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1427static const struct kernel_symbol *resolve_symbol(struct module *mod,
1428 const struct load_info *info,
1429 const char *name,
1430 char ownername[])
1431{
1432 struct module *owner;
1433 const struct kernel_symbol *sym;
1434 const s32 *crc;
1435 int err;
1436
1437 /*
1438 * The module_mutex should not be a heavily contended lock;
1439 * if we get the occasional sleep here, we'll go an extra iteration
1440 * in the wait_event_interruptible(), which is harmless.
1441 */
1442 sched_annotate_sleep();
1443 mutex_lock(&module_mutex);
1444 sym = find_symbol(name, &owner, &crc,
1445 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1446 if (!sym)
1447 goto unlock;
1448
1449 if (!check_version(info, name, mod, crc)) {
1450 sym = ERR_PTR(-EINVAL);
1451 goto getname;
1452 }
1453
1454 err = verify_namespace_is_imported(info, sym, mod);
1455 if (err) {
1456 sym = ERR_PTR(err);
1457 goto getname;
1458 }
1459
1460 err = ref_module(mod, owner);
1461 if (err) {
1462 sym = ERR_PTR(err);
1463 goto getname;
1464 }
1465
1466getname:
1467 /* We must make copy under the lock if we failed to get ref. */
1468 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1469unlock:
1470 mutex_unlock(&module_mutex);
1471 return sym;
1472}
1473
1474static const struct kernel_symbol *
1475resolve_symbol_wait(struct module *mod,
1476 const struct load_info *info,
1477 const char *name)
1478{
1479 const struct kernel_symbol *ksym;
1480 char owner[MODULE_NAME_LEN];
1481
1482 if (wait_event_interruptible_timeout(module_wq,
1483 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1484 || PTR_ERR(ksym) != -EBUSY,
1485 30 * HZ) <= 0) {
1486 pr_warn("%s: gave up waiting for init of module %s.\n",
1487 mod->name, owner);
1488 }
1489 return ksym;
1490}
1491
1492/*
1493 * /sys/module/foo/sections stuff
1494 * J. Corbet <corbet@lwn.net>
1495 */
1496#ifdef CONFIG_SYSFS
1497
1498#ifdef CONFIG_KALLSYMS
1499static inline bool sect_empty(const Elf_Shdr *sect)
1500{
1501 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1502}
1503
1504struct module_sect_attr {
1505 struct module_attribute mattr;
1506 char *name;
1507 unsigned long address;
1508};
1509
1510struct module_sect_attrs {
1511 struct attribute_group grp;
1512 unsigned int nsections;
1513 struct module_sect_attr attrs[0];
1514};
1515
1516static ssize_t module_sect_show(struct module_attribute *mattr,
1517 struct module_kobject *mk, char *buf)
1518{
1519 struct module_sect_attr *sattr =
1520 container_of(mattr, struct module_sect_attr, mattr);
1521 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1522 (void *)sattr->address : NULL);
1523}
1524
1525static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1526{
1527 unsigned int section;
1528
1529 for (section = 0; section < sect_attrs->nsections; section++)
1530 kfree(sect_attrs->attrs[section].name);
1531 kfree(sect_attrs);
1532}
1533
1534static void add_sect_attrs(struct module *mod, const struct load_info *info)
1535{
1536 unsigned int nloaded = 0, i, size[2];
1537 struct module_sect_attrs *sect_attrs;
1538 struct module_sect_attr *sattr;
1539 struct attribute **gattr;
1540
1541 /* Count loaded sections and allocate structures */
1542 for (i = 0; i < info->hdr->e_shnum; i++)
1543 if (!sect_empty(&info->sechdrs[i]))
1544 nloaded++;
1545 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1546 sizeof(sect_attrs->grp.attrs[0]));
1547 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1548 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1549 if (sect_attrs == NULL)
1550 return;
1551
1552 /* Setup section attributes. */
1553 sect_attrs->grp.name = "sections";
1554 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1555
1556 sect_attrs->nsections = 0;
1557 sattr = §_attrs->attrs[0];
1558 gattr = §_attrs->grp.attrs[0];
1559 for (i = 0; i < info->hdr->e_shnum; i++) {
1560 Elf_Shdr *sec = &info->sechdrs[i];
1561 if (sect_empty(sec))
1562 continue;
1563 sattr->address = sec->sh_addr;
1564 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1565 GFP_KERNEL);
1566 if (sattr->name == NULL)
1567 goto out;
1568 sect_attrs->nsections++;
1569 sysfs_attr_init(&sattr->mattr.attr);
1570 sattr->mattr.show = module_sect_show;
1571 sattr->mattr.store = NULL;
1572 sattr->mattr.attr.name = sattr->name;
1573 sattr->mattr.attr.mode = S_IRUSR;
1574 *(gattr++) = &(sattr++)->mattr.attr;
1575 }
1576 *gattr = NULL;
1577
1578 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1579 goto out;
1580
1581 mod->sect_attrs = sect_attrs;
1582 return;
1583 out:
1584 free_sect_attrs(sect_attrs);
1585}
1586
1587static void remove_sect_attrs(struct module *mod)
1588{
1589 if (mod->sect_attrs) {
1590 sysfs_remove_group(&mod->mkobj.kobj,
1591 &mod->sect_attrs->grp);
1592 /* We are positive that no one is using any sect attrs
1593 * at this point. Deallocate immediately. */
1594 free_sect_attrs(mod->sect_attrs);
1595 mod->sect_attrs = NULL;
1596 }
1597}
1598
1599/*
1600 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1601 */
1602
1603struct module_notes_attrs {
1604 struct kobject *dir;
1605 unsigned int notes;
1606 struct bin_attribute attrs[0];
1607};
1608
1609static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1610 struct bin_attribute *bin_attr,
1611 char *buf, loff_t pos, size_t count)
1612{
1613 /*
1614 * The caller checked the pos and count against our size.
1615 */
1616 memcpy(buf, bin_attr->private + pos, count);
1617 return count;
1618}
1619
1620static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1621 unsigned int i)
1622{
1623 if (notes_attrs->dir) {
1624 while (i-- > 0)
1625 sysfs_remove_bin_file(notes_attrs->dir,
1626 ¬es_attrs->attrs[i]);
1627 kobject_put(notes_attrs->dir);
1628 }
1629 kfree(notes_attrs);
1630}
1631
1632static void add_notes_attrs(struct module *mod, const struct load_info *info)
1633{
1634 unsigned int notes, loaded, i;
1635 struct module_notes_attrs *notes_attrs;
1636 struct bin_attribute *nattr;
1637
1638 /* failed to create section attributes, so can't create notes */
1639 if (!mod->sect_attrs)
1640 return;
1641
1642 /* Count notes sections and allocate structures. */
1643 notes = 0;
1644 for (i = 0; i < info->hdr->e_shnum; i++)
1645 if (!sect_empty(&info->sechdrs[i]) &&
1646 (info->sechdrs[i].sh_type == SHT_NOTE))
1647 ++notes;
1648
1649 if (notes == 0)
1650 return;
1651
1652 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1653 GFP_KERNEL);
1654 if (notes_attrs == NULL)
1655 return;
1656
1657 notes_attrs->notes = notes;
1658 nattr = ¬es_attrs->attrs[0];
1659 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1660 if (sect_empty(&info->sechdrs[i]))
1661 continue;
1662 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1663 sysfs_bin_attr_init(nattr);
1664 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1665 nattr->attr.mode = S_IRUGO;
1666 nattr->size = info->sechdrs[i].sh_size;
1667 nattr->private = (void *) info->sechdrs[i].sh_addr;
1668 nattr->read = module_notes_read;
1669 ++nattr;
1670 }
1671 ++loaded;
1672 }
1673
1674 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1675 if (!notes_attrs->dir)
1676 goto out;
1677
1678 for (i = 0; i < notes; ++i)
1679 if (sysfs_create_bin_file(notes_attrs->dir,
1680 ¬es_attrs->attrs[i]))
1681 goto out;
1682
1683 mod->notes_attrs = notes_attrs;
1684 return;
1685
1686 out:
1687 free_notes_attrs(notes_attrs, i);
1688}
1689
1690static void remove_notes_attrs(struct module *mod)
1691{
1692 if (mod->notes_attrs)
1693 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1694}
1695
1696#else
1697
1698static inline void add_sect_attrs(struct module *mod,
1699 const struct load_info *info)
1700{
1701}
1702
1703static inline void remove_sect_attrs(struct module *mod)
1704{
1705}
1706
1707static inline void add_notes_attrs(struct module *mod,
1708 const struct load_info *info)
1709{
1710}
1711
1712static inline void remove_notes_attrs(struct module *mod)
1713{
1714}
1715#endif /* CONFIG_KALLSYMS */
1716
1717static void del_usage_links(struct module *mod)
1718{
1719#ifdef CONFIG_MODULE_UNLOAD
1720 struct module_use *use;
1721
1722 mutex_lock(&module_mutex);
1723 list_for_each_entry(use, &mod->target_list, target_list)
1724 sysfs_remove_link(use->target->holders_dir, mod->name);
1725 mutex_unlock(&module_mutex);
1726#endif
1727}
1728
1729static int add_usage_links(struct module *mod)
1730{
1731 int ret = 0;
1732#ifdef CONFIG_MODULE_UNLOAD
1733 struct module_use *use;
1734
1735 mutex_lock(&module_mutex);
1736 list_for_each_entry(use, &mod->target_list, target_list) {
1737 ret = sysfs_create_link(use->target->holders_dir,
1738 &mod->mkobj.kobj, mod->name);
1739 if (ret)
1740 break;
1741 }
1742 mutex_unlock(&module_mutex);
1743 if (ret)
1744 del_usage_links(mod);
1745#endif
1746 return ret;
1747}
1748
1749static void module_remove_modinfo_attrs(struct module *mod, int end);
1750
1751static int module_add_modinfo_attrs(struct module *mod)
1752{
1753 struct module_attribute *attr;
1754 struct module_attribute *temp_attr;
1755 int error = 0;
1756 int i;
1757
1758 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1759 (ARRAY_SIZE(modinfo_attrs) + 1)),
1760 GFP_KERNEL);
1761 if (!mod->modinfo_attrs)
1762 return -ENOMEM;
1763
1764 temp_attr = mod->modinfo_attrs;
1765 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1766 if (!attr->test || attr->test(mod)) {
1767 memcpy(temp_attr, attr, sizeof(*temp_attr));
1768 sysfs_attr_init(&temp_attr->attr);
1769 error = sysfs_create_file(&mod->mkobj.kobj,
1770 &temp_attr->attr);
1771 if (error)
1772 goto error_out;
1773 ++temp_attr;
1774 }
1775 }
1776
1777 return 0;
1778
1779error_out:
1780 if (i > 0)
1781 module_remove_modinfo_attrs(mod, --i);
1782 return error;
1783}
1784
1785static void module_remove_modinfo_attrs(struct module *mod, int end)
1786{
1787 struct module_attribute *attr;
1788 int i;
1789
1790 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1791 if (end >= 0 && i > end)
1792 break;
1793 /* pick a field to test for end of list */
1794 if (!attr->attr.name)
1795 break;
1796 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1797 if (attr->free)
1798 attr->free(mod);
1799 }
1800 kfree(mod->modinfo_attrs);
1801}
1802
1803static void mod_kobject_put(struct module *mod)
1804{
1805 DECLARE_COMPLETION_ONSTACK(c);
1806 mod->mkobj.kobj_completion = &c;
1807 kobject_put(&mod->mkobj.kobj);
1808 wait_for_completion(&c);
1809}
1810
1811static int mod_sysfs_init(struct module *mod)
1812{
1813 int err;
1814 struct kobject *kobj;
1815
1816 if (!module_sysfs_initialized) {
1817 pr_err("%s: module sysfs not initialized\n", mod->name);
1818 err = -EINVAL;
1819 goto out;
1820 }
1821
1822 kobj = kset_find_obj(module_kset, mod->name);
1823 if (kobj) {
1824 pr_err("%s: module is already loaded\n", mod->name);
1825 kobject_put(kobj);
1826 err = -EINVAL;
1827 goto out;
1828 }
1829
1830 mod->mkobj.mod = mod;
1831
1832 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1833 mod->mkobj.kobj.kset = module_kset;
1834 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1835 "%s", mod->name);
1836 if (err)
1837 mod_kobject_put(mod);
1838
1839 /* delay uevent until full sysfs population */
1840out:
1841 return err;
1842}
1843
1844static int mod_sysfs_setup(struct module *mod,
1845 const struct load_info *info,
1846 struct kernel_param *kparam,
1847 unsigned int num_params)
1848{
1849 int err;
1850
1851 err = mod_sysfs_init(mod);
1852 if (err)
1853 goto out;
1854
1855 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1856 if (!mod->holders_dir) {
1857 err = -ENOMEM;
1858 goto out_unreg;
1859 }
1860
1861 err = module_param_sysfs_setup(mod, kparam, num_params);
1862 if (err)
1863 goto out_unreg_holders;
1864
1865 err = module_add_modinfo_attrs(mod);
1866 if (err)
1867 goto out_unreg_param;
1868
1869 err = add_usage_links(mod);
1870 if (err)
1871 goto out_unreg_modinfo_attrs;
1872
1873 add_sect_attrs(mod, info);
1874 add_notes_attrs(mod, info);
1875
1876 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1877 return 0;
1878
1879out_unreg_modinfo_attrs:
1880 module_remove_modinfo_attrs(mod, -1);
1881out_unreg_param:
1882 module_param_sysfs_remove(mod);
1883out_unreg_holders:
1884 kobject_put(mod->holders_dir);
1885out_unreg:
1886 mod_kobject_put(mod);
1887out:
1888 return err;
1889}
1890
1891static void mod_sysfs_fini(struct module *mod)
1892{
1893 remove_notes_attrs(mod);
1894 remove_sect_attrs(mod);
1895 mod_kobject_put(mod);
1896}
1897
1898static void init_param_lock(struct module *mod)
1899{
1900 mutex_init(&mod->param_lock);
1901}
1902#else /* !CONFIG_SYSFS */
1903
1904static int mod_sysfs_setup(struct module *mod,
1905 const struct load_info *info,
1906 struct kernel_param *kparam,
1907 unsigned int num_params)
1908{
1909 return 0;
1910}
1911
1912static void mod_sysfs_fini(struct module *mod)
1913{
1914}
1915
1916static void module_remove_modinfo_attrs(struct module *mod, int end)
1917{
1918}
1919
1920static void del_usage_links(struct module *mod)
1921{
1922}
1923
1924static void init_param_lock(struct module *mod)
1925{
1926}
1927#endif /* CONFIG_SYSFS */
1928
1929static void mod_sysfs_teardown(struct module *mod)
1930{
1931 del_usage_links(mod);
1932 module_remove_modinfo_attrs(mod, -1);
1933 module_param_sysfs_remove(mod);
1934 kobject_put(mod->mkobj.drivers_dir);
1935 kobject_put(mod->holders_dir);
1936 mod_sysfs_fini(mod);
1937}
1938
1939#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1940/*
1941 * LKM RO/NX protection: protect module's text/ro-data
1942 * from modification and any data from execution.
1943 *
1944 * General layout of module is:
1945 * [text] [read-only-data] [ro-after-init] [writable data]
1946 * text_size -----^ ^ ^ ^
1947 * ro_size ------------------------| | |
1948 * ro_after_init_size -----------------------------| |
1949 * size -----------------------------------------------------------|
1950 *
1951 * These values are always page-aligned (as is base)
1952 */
1953static void frob_text(const struct module_layout *layout,
1954 int (*set_memory)(unsigned long start, int num_pages))
1955{
1956 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1957 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1958 set_memory((unsigned long)layout->base,
1959 layout->text_size >> PAGE_SHIFT);
1960}
1961
1962#ifdef CONFIG_STRICT_MODULE_RWX
1963static void frob_rodata(const struct module_layout *layout,
1964 int (*set_memory)(unsigned long start, int num_pages))
1965{
1966 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1967 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1968 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1969 set_memory((unsigned long)layout->base + layout->text_size,
1970 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1971}
1972
1973static void frob_ro_after_init(const struct module_layout *layout,
1974 int (*set_memory)(unsigned long start, int num_pages))
1975{
1976 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1977 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1978 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1979 set_memory((unsigned long)layout->base + layout->ro_size,
1980 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1981}
1982
1983static void frob_writable_data(const struct module_layout *layout,
1984 int (*set_memory)(unsigned long start, int num_pages))
1985{
1986 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1987 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1988 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1989 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1990 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1991}
1992
1993/* livepatching wants to disable read-only so it can frob module. */
1994void module_disable_ro(const struct module *mod)
1995{
1996 if (!rodata_enabled)
1997 return;
1998
1999 frob_text(&mod->core_layout, set_memory_rw);
2000 frob_rodata(&mod->core_layout, set_memory_rw);
2001 frob_ro_after_init(&mod->core_layout, set_memory_rw);
2002 frob_text(&mod->init_layout, set_memory_rw);
2003 frob_rodata(&mod->init_layout, set_memory_rw);
2004}
2005
2006void module_enable_ro(const struct module *mod, bool after_init)
2007{
2008 if (!rodata_enabled)
2009 return;
2010
2011 set_vm_flush_reset_perms(mod->core_layout.base);
2012 set_vm_flush_reset_perms(mod->init_layout.base);
2013 frob_text(&mod->core_layout, set_memory_ro);
2014
2015 frob_rodata(&mod->core_layout, set_memory_ro);
2016 frob_text(&mod->init_layout, set_memory_ro);
2017 frob_rodata(&mod->init_layout, set_memory_ro);
2018
2019 if (after_init)
2020 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2021}
2022
2023static void module_enable_nx(const struct module *mod)
2024{
2025 frob_rodata(&mod->core_layout, set_memory_nx);
2026 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2027 frob_writable_data(&mod->core_layout, set_memory_nx);
2028 frob_rodata(&mod->init_layout, set_memory_nx);
2029 frob_writable_data(&mod->init_layout, set_memory_nx);
2030}
2031
2032/* Iterate through all modules and set each module's text as RW */
2033void set_all_modules_text_rw(void)
2034{
2035 struct module *mod;
2036
2037 if (!rodata_enabled)
2038 return;
2039
2040 mutex_lock(&module_mutex);
2041 list_for_each_entry_rcu(mod, &modules, list) {
2042 if (mod->state == MODULE_STATE_UNFORMED)
2043 continue;
2044
2045 frob_text(&mod->core_layout, set_memory_rw);
2046 frob_text(&mod->init_layout, set_memory_rw);
2047 }
2048 mutex_unlock(&module_mutex);
2049}
2050
2051/* Iterate through all modules and set each module's text as RO */
2052void set_all_modules_text_ro(void)
2053{
2054 struct module *mod;
2055
2056 if (!rodata_enabled)
2057 return;
2058
2059 mutex_lock(&module_mutex);
2060 list_for_each_entry_rcu(mod, &modules, list) {
2061 /*
2062 * Ignore going modules since it's possible that ro
2063 * protection has already been disabled, otherwise we'll
2064 * run into protection faults at module deallocation.
2065 */
2066 if (mod->state == MODULE_STATE_UNFORMED ||
2067 mod->state == MODULE_STATE_GOING)
2068 continue;
2069
2070 frob_text(&mod->core_layout, set_memory_ro);
2071 frob_text(&mod->init_layout, set_memory_ro);
2072 }
2073 mutex_unlock(&module_mutex);
2074}
2075#else /* !CONFIG_STRICT_MODULE_RWX */
2076static void module_enable_nx(const struct module *mod) { }
2077#endif /* CONFIG_STRICT_MODULE_RWX */
2078static void module_enable_x(const struct module *mod)
2079{
2080 frob_text(&mod->core_layout, set_memory_x);
2081 frob_text(&mod->init_layout, set_memory_x);
2082}
2083#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2084static void module_enable_nx(const struct module *mod) { }
2085static void module_enable_x(const struct module *mod) { }
2086#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2087
2088
2089#ifdef CONFIG_LIVEPATCH
2090/*
2091 * Persist Elf information about a module. Copy the Elf header,
2092 * section header table, section string table, and symtab section
2093 * index from info to mod->klp_info.
2094 */
2095static int copy_module_elf(struct module *mod, struct load_info *info)
2096{
2097 unsigned int size, symndx;
2098 int ret;
2099
2100 size = sizeof(*mod->klp_info);
2101 mod->klp_info = kmalloc(size, GFP_KERNEL);
2102 if (mod->klp_info == NULL)
2103 return -ENOMEM;
2104
2105 /* Elf header */
2106 size = sizeof(mod->klp_info->hdr);
2107 memcpy(&mod->klp_info->hdr, info->hdr, size);
2108
2109 /* Elf section header table */
2110 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2111 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2112 if (mod->klp_info->sechdrs == NULL) {
2113 ret = -ENOMEM;
2114 goto free_info;
2115 }
2116
2117 /* Elf section name string table */
2118 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2119 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2120 if (mod->klp_info->secstrings == NULL) {
2121 ret = -ENOMEM;
2122 goto free_sechdrs;
2123 }
2124
2125 /* Elf symbol section index */
2126 symndx = info->index.sym;
2127 mod->klp_info->symndx = symndx;
2128
2129 /*
2130 * For livepatch modules, core_kallsyms.symtab is a complete
2131 * copy of the original symbol table. Adjust sh_addr to point
2132 * to core_kallsyms.symtab since the copy of the symtab in module
2133 * init memory is freed at the end of do_init_module().
2134 */
2135 mod->klp_info->sechdrs[symndx].sh_addr = \
2136 (unsigned long) mod->core_kallsyms.symtab;
2137
2138 return 0;
2139
2140free_sechdrs:
2141 kfree(mod->klp_info->sechdrs);
2142free_info:
2143 kfree(mod->klp_info);
2144 return ret;
2145}
2146
2147static void free_module_elf(struct module *mod)
2148{
2149 kfree(mod->klp_info->sechdrs);
2150 kfree(mod->klp_info->secstrings);
2151 kfree(mod->klp_info);
2152}
2153#else /* !CONFIG_LIVEPATCH */
2154static int copy_module_elf(struct module *mod, struct load_info *info)
2155{
2156 return 0;
2157}
2158
2159static void free_module_elf(struct module *mod)
2160{
2161}
2162#endif /* CONFIG_LIVEPATCH */
2163
2164void __weak module_memfree(void *module_region)
2165{
2166 /*
2167 * This memory may be RO, and freeing RO memory in an interrupt is not
2168 * supported by vmalloc.
2169 */
2170 WARN_ON(in_interrupt());
2171 vfree(module_region);
2172}
2173
2174void __weak module_arch_cleanup(struct module *mod)
2175{
2176}
2177
2178void __weak module_arch_freeing_init(struct module *mod)
2179{
2180}
2181
2182/* Free a module, remove from lists, etc. */
2183static void free_module(struct module *mod)
2184{
2185 trace_module_free(mod);
2186
2187 mod_sysfs_teardown(mod);
2188
2189 /* We leave it in list to prevent duplicate loads, but make sure
2190 * that noone uses it while it's being deconstructed. */
2191 mutex_lock(&module_mutex);
2192 mod->state = MODULE_STATE_UNFORMED;
2193 mutex_unlock(&module_mutex);
2194
2195 /* Remove dynamic debug info */
2196 ddebug_remove_module(mod->name);
2197
2198 /* Arch-specific cleanup. */
2199 module_arch_cleanup(mod);
2200
2201 /* Module unload stuff */
2202 module_unload_free(mod);
2203
2204 /* Free any allocated parameters. */
2205 destroy_params(mod->kp, mod->num_kp);
2206
2207 if (is_livepatch_module(mod))
2208 free_module_elf(mod);
2209
2210 /* Now we can delete it from the lists */
2211 mutex_lock(&module_mutex);
2212 /* Unlink carefully: kallsyms could be walking list. */
2213 list_del_rcu(&mod->list);
2214 mod_tree_remove(mod);
2215 /* Remove this module from bug list, this uses list_del_rcu */
2216 module_bug_cleanup(mod);
2217 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2218 synchronize_rcu();
2219 mutex_unlock(&module_mutex);
2220
2221 /* This may be empty, but that's OK */
2222 module_arch_freeing_init(mod);
2223 module_memfree(mod->init_layout.base);
2224 kfree(mod->args);
2225 percpu_modfree(mod);
2226
2227 /* Free lock-classes; relies on the preceding sync_rcu(). */
2228 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2229
2230 /* Finally, free the core (containing the module structure) */
2231 module_memfree(mod->core_layout.base);
2232}
2233
2234void *__symbol_get(const char *symbol)
2235{
2236 struct module *owner;
2237 const struct kernel_symbol *sym;
2238
2239 preempt_disable();
2240 sym = find_symbol(symbol, &owner, NULL, true, true);
2241 if (sym && strong_try_module_get(owner))
2242 sym = NULL;
2243 preempt_enable();
2244
2245 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2246}
2247EXPORT_SYMBOL_GPL(__symbol_get);
2248
2249/*
2250 * Ensure that an exported symbol [global namespace] does not already exist
2251 * in the kernel or in some other module's exported symbol table.
2252 *
2253 * You must hold the module_mutex.
2254 */
2255static int verify_exported_symbols(struct module *mod)
2256{
2257 unsigned int i;
2258 struct module *owner;
2259 const struct kernel_symbol *s;
2260 struct {
2261 const struct kernel_symbol *sym;
2262 unsigned int num;
2263 } arr[] = {
2264 { mod->syms, mod->num_syms },
2265 { mod->gpl_syms, mod->num_gpl_syms },
2266 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2267#ifdef CONFIG_UNUSED_SYMBOLS
2268 { mod->unused_syms, mod->num_unused_syms },
2269 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2270#endif
2271 };
2272
2273 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2274 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2275 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2276 true, false)) {
2277 pr_err("%s: exports duplicate symbol %s"
2278 " (owned by %s)\n",
2279 mod->name, kernel_symbol_name(s),
2280 module_name(owner));
2281 return -ENOEXEC;
2282 }
2283 }
2284 }
2285 return 0;
2286}
2287
2288/* Change all symbols so that st_value encodes the pointer directly. */
2289static int simplify_symbols(struct module *mod, const struct load_info *info)
2290{
2291 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2292 Elf_Sym *sym = (void *)symsec->sh_addr;
2293 unsigned long secbase;
2294 unsigned int i;
2295 int ret = 0;
2296 const struct kernel_symbol *ksym;
2297
2298 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2299 const char *name = info->strtab + sym[i].st_name;
2300
2301 switch (sym[i].st_shndx) {
2302 case SHN_COMMON:
2303 /* Ignore common symbols */
2304 if (!strncmp(name, "__gnu_lto", 9))
2305 break;
2306
2307 /* We compiled with -fno-common. These are not
2308 supposed to happen. */
2309 pr_debug("Common symbol: %s\n", name);
2310 pr_warn("%s: please compile with -fno-common\n",
2311 mod->name);
2312 ret = -ENOEXEC;
2313 break;
2314
2315 case SHN_ABS:
2316 /* Don't need to do anything */
2317 pr_debug("Absolute symbol: 0x%08lx\n",
2318 (long)sym[i].st_value);
2319 break;
2320
2321 case SHN_LIVEPATCH:
2322 /* Livepatch symbols are resolved by livepatch */
2323 break;
2324
2325 case SHN_UNDEF:
2326 ksym = resolve_symbol_wait(mod, info, name);
2327 /* Ok if resolved. */
2328 if (ksym && !IS_ERR(ksym)) {
2329 sym[i].st_value = kernel_symbol_value(ksym);
2330 break;
2331 }
2332
2333 /* Ok if weak. */
2334 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2335 break;
2336
2337 ret = PTR_ERR(ksym) ?: -ENOENT;
2338 pr_warn("%s: Unknown symbol %s (err %d)\n",
2339 mod->name, name, ret);
2340 break;
2341
2342 default:
2343 /* Divert to percpu allocation if a percpu var. */
2344 if (sym[i].st_shndx == info->index.pcpu)
2345 secbase = (unsigned long)mod_percpu(mod);
2346 else
2347 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2348 sym[i].st_value += secbase;
2349 break;
2350 }
2351 }
2352
2353 return ret;
2354}
2355
2356static int apply_relocations(struct module *mod, const struct load_info *info)
2357{
2358 unsigned int i;
2359 int err = 0;
2360
2361 /* Now do relocations. */
2362 for (i = 1; i < info->hdr->e_shnum; i++) {
2363 unsigned int infosec = info->sechdrs[i].sh_info;
2364
2365 /* Not a valid relocation section? */
2366 if (infosec >= info->hdr->e_shnum)
2367 continue;
2368
2369 /* Don't bother with non-allocated sections */
2370 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2371 continue;
2372
2373 /* Livepatch relocation sections are applied by livepatch */
2374 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2375 continue;
2376
2377 if (info->sechdrs[i].sh_type == SHT_REL)
2378 err = apply_relocate(info->sechdrs, info->strtab,
2379 info->index.sym, i, mod);
2380 else if (info->sechdrs[i].sh_type == SHT_RELA)
2381 err = apply_relocate_add(info->sechdrs, info->strtab,
2382 info->index.sym, i, mod);
2383 if (err < 0)
2384 break;
2385 }
2386 return err;
2387}
2388
2389/* Additional bytes needed by arch in front of individual sections */
2390unsigned int __weak arch_mod_section_prepend(struct module *mod,
2391 unsigned int section)
2392{
2393 /* default implementation just returns zero */
2394 return 0;
2395}
2396
2397/* Update size with this section: return offset. */
2398static long get_offset(struct module *mod, unsigned int *size,
2399 Elf_Shdr *sechdr, unsigned int section)
2400{
2401 long ret;
2402
2403 *size += arch_mod_section_prepend(mod, section);
2404 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2405 *size = ret + sechdr->sh_size;
2406 return ret;
2407}
2408
2409/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2410 might -- code, read-only data, read-write data, small data. Tally
2411 sizes, and place the offsets into sh_entsize fields: high bit means it
2412 belongs in init. */
2413static void layout_sections(struct module *mod, struct load_info *info)
2414{
2415 static unsigned long const masks[][2] = {
2416 /* NOTE: all executable code must be the first section
2417 * in this array; otherwise modify the text_size
2418 * finder in the two loops below */
2419 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2420 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2421 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2422 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2423 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2424 };
2425 unsigned int m, i;
2426
2427 for (i = 0; i < info->hdr->e_shnum; i++)
2428 info->sechdrs[i].sh_entsize = ~0UL;
2429
2430 pr_debug("Core section allocation order:\n");
2431 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2432 for (i = 0; i < info->hdr->e_shnum; ++i) {
2433 Elf_Shdr *s = &info->sechdrs[i];
2434 const char *sname = info->secstrings + s->sh_name;
2435
2436 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2437 || (s->sh_flags & masks[m][1])
2438 || s->sh_entsize != ~0UL
2439 || strstarts(sname, ".init"))
2440 continue;
2441 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2442 pr_debug("\t%s\n", sname);
2443 }
2444 switch (m) {
2445 case 0: /* executable */
2446 mod->core_layout.size = debug_align(mod->core_layout.size);
2447 mod->core_layout.text_size = mod->core_layout.size;
2448 break;
2449 case 1: /* RO: text and ro-data */
2450 mod->core_layout.size = debug_align(mod->core_layout.size);
2451 mod->core_layout.ro_size = mod->core_layout.size;
2452 break;
2453 case 2: /* RO after init */
2454 mod->core_layout.size = debug_align(mod->core_layout.size);
2455 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2456 break;
2457 case 4: /* whole core */
2458 mod->core_layout.size = debug_align(mod->core_layout.size);
2459 break;
2460 }
2461 }
2462
2463 pr_debug("Init section allocation order:\n");
2464 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2465 for (i = 0; i < info->hdr->e_shnum; ++i) {
2466 Elf_Shdr *s = &info->sechdrs[i];
2467 const char *sname = info->secstrings + s->sh_name;
2468
2469 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2470 || (s->sh_flags & masks[m][1])
2471 || s->sh_entsize != ~0UL
2472 || !strstarts(sname, ".init"))
2473 continue;
2474 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2475 | INIT_OFFSET_MASK);
2476 pr_debug("\t%s\n", sname);
2477 }
2478 switch (m) {
2479 case 0: /* executable */
2480 mod->init_layout.size = debug_align(mod->init_layout.size);
2481 mod->init_layout.text_size = mod->init_layout.size;
2482 break;
2483 case 1: /* RO: text and ro-data */
2484 mod->init_layout.size = debug_align(mod->init_layout.size);
2485 mod->init_layout.ro_size = mod->init_layout.size;
2486 break;
2487 case 2:
2488 /*
2489 * RO after init doesn't apply to init_layout (only
2490 * core_layout), so it just takes the value of ro_size.
2491 */
2492 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2493 break;
2494 case 4: /* whole init */
2495 mod->init_layout.size = debug_align(mod->init_layout.size);
2496 break;
2497 }
2498 }
2499}
2500
2501static void set_license(struct module *mod, const char *license)
2502{
2503 if (!license)
2504 license = "unspecified";
2505
2506 if (!license_is_gpl_compatible(license)) {
2507 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2508 pr_warn("%s: module license '%s' taints kernel.\n",
2509 mod->name, license);
2510 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2511 LOCKDEP_NOW_UNRELIABLE);
2512 }
2513}
2514
2515/* Parse tag=value strings from .modinfo section */
2516static char *next_string(char *string, unsigned long *secsize)
2517{
2518 /* Skip non-zero chars */
2519 while (string[0]) {
2520 string++;
2521 if ((*secsize)-- <= 1)
2522 return NULL;
2523 }
2524
2525 /* Skip any zero padding. */
2526 while (!string[0]) {
2527 string++;
2528 if ((*secsize)-- <= 1)
2529 return NULL;
2530 }
2531 return string;
2532}
2533
2534static char *get_next_modinfo(const struct load_info *info, const char *tag,
2535 char *prev)
2536{
2537 char *p;
2538 unsigned int taglen = strlen(tag);
2539 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2540 unsigned long size = infosec->sh_size;
2541
2542 /*
2543 * get_modinfo() calls made before rewrite_section_headers()
2544 * must use sh_offset, as sh_addr isn't set!
2545 */
2546 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2547
2548 if (prev) {
2549 size -= prev - modinfo;
2550 modinfo = next_string(prev, &size);
2551 }
2552
2553 for (p = modinfo; p; p = next_string(p, &size)) {
2554 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2555 return p + taglen + 1;
2556 }
2557 return NULL;
2558}
2559
2560static char *get_modinfo(const struct load_info *info, const char *tag)
2561{
2562 return get_next_modinfo(info, tag, NULL);
2563}
2564
2565static void setup_modinfo(struct module *mod, struct load_info *info)
2566{
2567 struct module_attribute *attr;
2568 int i;
2569
2570 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2571 if (attr->setup)
2572 attr->setup(mod, get_modinfo(info, attr->attr.name));
2573 }
2574}
2575
2576static void free_modinfo(struct module *mod)
2577{
2578 struct module_attribute *attr;
2579 int i;
2580
2581 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2582 if (attr->free)
2583 attr->free(mod);
2584 }
2585}
2586
2587#ifdef CONFIG_KALLSYMS
2588
2589/* Lookup exported symbol in given range of kernel_symbols */
2590static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2591 const struct kernel_symbol *start,
2592 const struct kernel_symbol *stop)
2593{
2594 return bsearch(name, start, stop - start,
2595 sizeof(struct kernel_symbol), cmp_name);
2596}
2597
2598static int is_exported(const char *name, unsigned long value,
2599 const struct module *mod)
2600{
2601 const struct kernel_symbol *ks;
2602 if (!mod)
2603 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2604 else
2605 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2606
2607 return ks != NULL && kernel_symbol_value(ks) == value;
2608}
2609
2610/* As per nm */
2611static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2612{
2613 const Elf_Shdr *sechdrs = info->sechdrs;
2614
2615 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2616 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2617 return 'v';
2618 else
2619 return 'w';
2620 }
2621 if (sym->st_shndx == SHN_UNDEF)
2622 return 'U';
2623 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2624 return 'a';
2625 if (sym->st_shndx >= SHN_LORESERVE)
2626 return '?';
2627 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2628 return 't';
2629 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2630 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2631 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2632 return 'r';
2633 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2634 return 'g';
2635 else
2636 return 'd';
2637 }
2638 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2639 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2640 return 's';
2641 else
2642 return 'b';
2643 }
2644 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2645 ".debug")) {
2646 return 'n';
2647 }
2648 return '?';
2649}
2650
2651static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2652 unsigned int shnum, unsigned int pcpundx)
2653{
2654 const Elf_Shdr *sec;
2655
2656 if (src->st_shndx == SHN_UNDEF
2657 || src->st_shndx >= shnum
2658 || !src->st_name)
2659 return false;
2660
2661#ifdef CONFIG_KALLSYMS_ALL
2662 if (src->st_shndx == pcpundx)
2663 return true;
2664#endif
2665
2666 sec = sechdrs + src->st_shndx;
2667 if (!(sec->sh_flags & SHF_ALLOC)
2668#ifndef CONFIG_KALLSYMS_ALL
2669 || !(sec->sh_flags & SHF_EXECINSTR)
2670#endif
2671 || (sec->sh_entsize & INIT_OFFSET_MASK))
2672 return false;
2673
2674 return true;
2675}
2676
2677/*
2678 * We only allocate and copy the strings needed by the parts of symtab
2679 * we keep. This is simple, but has the effect of making multiple
2680 * copies of duplicates. We could be more sophisticated, see
2681 * linux-kernel thread starting with
2682 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2683 */
2684static void layout_symtab(struct module *mod, struct load_info *info)
2685{
2686 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2687 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2688 const Elf_Sym *src;
2689 unsigned int i, nsrc, ndst, strtab_size = 0;
2690
2691 /* Put symbol section at end of init part of module. */
2692 symsect->sh_flags |= SHF_ALLOC;
2693 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2694 info->index.sym) | INIT_OFFSET_MASK;
2695 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2696
2697 src = (void *)info->hdr + symsect->sh_offset;
2698 nsrc = symsect->sh_size / sizeof(*src);
2699
2700 /* Compute total space required for the core symbols' strtab. */
2701 for (ndst = i = 0; i < nsrc; i++) {
2702 if (i == 0 || is_livepatch_module(mod) ||
2703 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2704 info->index.pcpu)) {
2705 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2706 ndst++;
2707 }
2708 }
2709
2710 /* Append room for core symbols at end of core part. */
2711 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2712 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2713 mod->core_layout.size += strtab_size;
2714 info->core_typeoffs = mod->core_layout.size;
2715 mod->core_layout.size += ndst * sizeof(char);
2716 mod->core_layout.size = debug_align(mod->core_layout.size);
2717
2718 /* Put string table section at end of init part of module. */
2719 strsect->sh_flags |= SHF_ALLOC;
2720 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2721 info->index.str) | INIT_OFFSET_MASK;
2722 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2723
2724 /* We'll tack temporary mod_kallsyms on the end. */
2725 mod->init_layout.size = ALIGN(mod->init_layout.size,
2726 __alignof__(struct mod_kallsyms));
2727 info->mod_kallsyms_init_off = mod->init_layout.size;
2728 mod->init_layout.size += sizeof(struct mod_kallsyms);
2729 info->init_typeoffs = mod->init_layout.size;
2730 mod->init_layout.size += nsrc * sizeof(char);
2731 mod->init_layout.size = debug_align(mod->init_layout.size);
2732}
2733
2734/*
2735 * We use the full symtab and strtab which layout_symtab arranged to
2736 * be appended to the init section. Later we switch to the cut-down
2737 * core-only ones.
2738 */
2739static void add_kallsyms(struct module *mod, const struct load_info *info)
2740{
2741 unsigned int i, ndst;
2742 const Elf_Sym *src;
2743 Elf_Sym *dst;
2744 char *s;
2745 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2746
2747 /* Set up to point into init section. */
2748 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2749
2750 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2751 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2752 /* Make sure we get permanent strtab: don't use info->strtab. */
2753 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2754 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2755
2756 /*
2757 * Now populate the cut down core kallsyms for after init
2758 * and set types up while we still have access to sections.
2759 */
2760 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2761 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2762 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2763 src = mod->kallsyms->symtab;
2764 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2765 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2766 if (i == 0 || is_livepatch_module(mod) ||
2767 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2768 info->index.pcpu)) {
2769 mod->core_kallsyms.typetab[ndst] =
2770 mod->kallsyms->typetab[i];
2771 dst[ndst] = src[i];
2772 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2773 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2774 KSYM_NAME_LEN) + 1;
2775 }
2776 }
2777 mod->core_kallsyms.num_symtab = ndst;
2778}
2779#else
2780static inline void layout_symtab(struct module *mod, struct load_info *info)
2781{
2782}
2783
2784static void add_kallsyms(struct module *mod, const struct load_info *info)
2785{
2786}
2787#endif /* CONFIG_KALLSYMS */
2788
2789static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2790{
2791 if (!debug)
2792 return;
2793 ddebug_add_module(debug, num, mod->name);
2794}
2795
2796static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2797{
2798 if (debug)
2799 ddebug_remove_module(mod->name);
2800}
2801
2802void * __weak module_alloc(unsigned long size)
2803{
2804 return vmalloc_exec(size);
2805}
2806
2807bool __weak module_exit_section(const char *name)
2808{
2809 return strstarts(name, ".exit");
2810}
2811
2812#ifdef CONFIG_DEBUG_KMEMLEAK
2813static void kmemleak_load_module(const struct module *mod,
2814 const struct load_info *info)
2815{
2816 unsigned int i;
2817
2818 /* only scan the sections containing data */
2819 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2820
2821 for (i = 1; i < info->hdr->e_shnum; i++) {
2822 /* Scan all writable sections that's not executable */
2823 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2824 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2825 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2826 continue;
2827
2828 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2829 info->sechdrs[i].sh_size, GFP_KERNEL);
2830 }
2831}
2832#else
2833static inline void kmemleak_load_module(const struct module *mod,
2834 const struct load_info *info)
2835{
2836}
2837#endif
2838
2839#ifdef CONFIG_MODULE_SIG
2840static int module_sig_check(struct load_info *info, int flags)
2841{
2842 int err = -ENODATA;
2843 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2844 const char *reason;
2845 const void *mod = info->hdr;
2846
2847 /*
2848 * Require flags == 0, as a module with version information
2849 * removed is no longer the module that was signed
2850 */
2851 if (flags == 0 &&
2852 info->len > markerlen &&
2853 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2854 /* We truncate the module to discard the signature */
2855 info->len -= markerlen;
2856 err = mod_verify_sig(mod, info);
2857 }
2858
2859 switch (err) {
2860 case 0:
2861 info->sig_ok = true;
2862 return 0;
2863
2864 /* We don't permit modules to be loaded into trusted kernels
2865 * without a valid signature on them, but if we're not
2866 * enforcing, certain errors are non-fatal.
2867 */
2868 case -ENODATA:
2869 reason = "Loading of unsigned module";
2870 goto decide;
2871 case -ENOPKG:
2872 reason = "Loading of module with unsupported crypto";
2873 goto decide;
2874 case -ENOKEY:
2875 reason = "Loading of module with unavailable key";
2876 decide:
2877 if (is_module_sig_enforced()) {
2878 pr_notice("%s is rejected\n", reason);
2879 return -EKEYREJECTED;
2880 }
2881
2882 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2883
2884 /* All other errors are fatal, including nomem, unparseable
2885 * signatures and signature check failures - even if signatures
2886 * aren't required.
2887 */
2888 default:
2889 return err;
2890 }
2891}
2892#else /* !CONFIG_MODULE_SIG */
2893static int module_sig_check(struct load_info *info, int flags)
2894{
2895 return 0;
2896}
2897#endif /* !CONFIG_MODULE_SIG */
2898
2899/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2900static int elf_header_check(struct load_info *info)
2901{
2902 if (info->len < sizeof(*(info->hdr)))
2903 return -ENOEXEC;
2904
2905 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2906 || info->hdr->e_type != ET_REL
2907 || !elf_check_arch(info->hdr)
2908 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2909 return -ENOEXEC;
2910
2911 if (info->hdr->e_shoff >= info->len
2912 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2913 info->len - info->hdr->e_shoff))
2914 return -ENOEXEC;
2915
2916 return 0;
2917}
2918
2919#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2920
2921static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2922{
2923 do {
2924 unsigned long n = min(len, COPY_CHUNK_SIZE);
2925
2926 if (copy_from_user(dst, usrc, n) != 0)
2927 return -EFAULT;
2928 cond_resched();
2929 dst += n;
2930 usrc += n;
2931 len -= n;
2932 } while (len);
2933 return 0;
2934}
2935
2936#ifdef CONFIG_LIVEPATCH
2937static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2938{
2939 if (get_modinfo(info, "livepatch")) {
2940 mod->klp = true;
2941 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2942 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2943 mod->name);
2944 }
2945
2946 return 0;
2947}
2948#else /* !CONFIG_LIVEPATCH */
2949static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2950{
2951 if (get_modinfo(info, "livepatch")) {
2952 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2953 mod->name);
2954 return -ENOEXEC;
2955 }
2956
2957 return 0;
2958}
2959#endif /* CONFIG_LIVEPATCH */
2960
2961static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2962{
2963 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2964 return;
2965
2966 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2967 mod->name);
2968}
2969
2970/* Sets info->hdr and info->len. */
2971static int copy_module_from_user(const void __user *umod, unsigned long len,
2972 struct load_info *info)
2973{
2974 int err;
2975
2976 info->len = len;
2977 if (info->len < sizeof(*(info->hdr)))
2978 return -ENOEXEC;
2979
2980 err = security_kernel_load_data(LOADING_MODULE);
2981 if (err)
2982 return err;
2983
2984 /* Suck in entire file: we'll want most of it. */
2985 info->hdr = __vmalloc(info->len,
2986 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2987 if (!info->hdr)
2988 return -ENOMEM;
2989
2990 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2991 vfree(info->hdr);
2992 return -EFAULT;
2993 }
2994
2995 return 0;
2996}
2997
2998static void free_copy(struct load_info *info)
2999{
3000 vfree(info->hdr);
3001}
3002
3003static int rewrite_section_headers(struct load_info *info, int flags)
3004{
3005 unsigned int i;
3006
3007 /* This should always be true, but let's be sure. */
3008 info->sechdrs[0].sh_addr = 0;
3009
3010 for (i = 1; i < info->hdr->e_shnum; i++) {
3011 Elf_Shdr *shdr = &info->sechdrs[i];
3012 if (shdr->sh_type != SHT_NOBITS
3013 && info->len < shdr->sh_offset + shdr->sh_size) {
3014 pr_err("Module len %lu truncated\n", info->len);
3015 return -ENOEXEC;
3016 }
3017
3018 /* Mark all sections sh_addr with their address in the
3019 temporary image. */
3020 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3021
3022#ifndef CONFIG_MODULE_UNLOAD
3023 /* Don't load .exit sections */
3024 if (module_exit_section(info->secstrings+shdr->sh_name))
3025 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3026#endif
3027 }
3028
3029 /* Track but don't keep modinfo and version sections. */
3030 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3031 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3032
3033 return 0;
3034}
3035
3036/*
3037 * Set up our basic convenience variables (pointers to section headers,
3038 * search for module section index etc), and do some basic section
3039 * verification.
3040 *
3041 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3042 * will be allocated in move_module().
3043 */
3044static int setup_load_info(struct load_info *info, int flags)
3045{
3046 unsigned int i;
3047
3048 /* Set up the convenience variables */
3049 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3050 info->secstrings = (void *)info->hdr
3051 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
3052
3053 /* Try to find a name early so we can log errors with a module name */
3054 info->index.info = find_sec(info, ".modinfo");
3055 if (!info->index.info)
3056 info->name = "(missing .modinfo section)";
3057 else
3058 info->name = get_modinfo(info, "name");
3059
3060 /* Find internal symbols and strings. */
3061 for (i = 1; i < info->hdr->e_shnum; i++) {
3062 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3063 info->index.sym = i;
3064 info->index.str = info->sechdrs[i].sh_link;
3065 info->strtab = (char *)info->hdr
3066 + info->sechdrs[info->index.str].sh_offset;
3067 break;
3068 }
3069 }
3070
3071 if (info->index.sym == 0) {
3072 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
3073 return -ENOEXEC;
3074 }
3075
3076 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3077 if (!info->index.mod) {
3078 pr_warn("%s: No module found in object\n",
3079 info->name ?: "(missing .modinfo name field)");
3080 return -ENOEXEC;
3081 }
3082 /* This is temporary: point mod into copy of data. */
3083 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3084
3085 /*
3086 * If we didn't load the .modinfo 'name' field earlier, fall back to
3087 * on-disk struct mod 'name' field.
3088 */
3089 if (!info->name)
3090 info->name = info->mod->name;
3091
3092 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3093 info->index.vers = 0; /* Pretend no __versions section! */
3094 else
3095 info->index.vers = find_sec(info, "__versions");
3096
3097 info->index.pcpu = find_pcpusec(info);
3098
3099 return 0;
3100}
3101
3102static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3103{
3104 const char *modmagic = get_modinfo(info, "vermagic");
3105 int err;
3106
3107 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3108 modmagic = NULL;
3109
3110 /* This is allowed: modprobe --force will invalidate it. */
3111 if (!modmagic) {
3112 err = try_to_force_load(mod, "bad vermagic");
3113 if (err)
3114 return err;
3115 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3116 pr_err("%s: version magic '%s' should be '%s'\n",
3117 info->name, modmagic, vermagic);
3118 return -ENOEXEC;
3119 }
3120
3121 if (!get_modinfo(info, "intree")) {
3122 if (!test_taint(TAINT_OOT_MODULE))
3123 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3124 mod->name);
3125 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3126 }
3127
3128 check_modinfo_retpoline(mod, info);
3129
3130 if (get_modinfo(info, "staging")) {
3131 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3132 pr_warn("%s: module is from the staging directory, the quality "
3133 "is unknown, you have been warned.\n", mod->name);
3134 }
3135
3136 err = check_modinfo_livepatch(mod, info);
3137 if (err)
3138 return err;
3139
3140 /* Set up license info based on the info section */
3141 set_license(mod, get_modinfo(info, "license"));
3142
3143 return 0;
3144}
3145
3146static int find_module_sections(struct module *mod, struct load_info *info)
3147{
3148 mod->kp = section_objs(info, "__param",
3149 sizeof(*mod->kp), &mod->num_kp);
3150 mod->syms = section_objs(info, "__ksymtab",
3151 sizeof(*mod->syms), &mod->num_syms);
3152 mod->crcs = section_addr(info, "__kcrctab");
3153 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3154 sizeof(*mod->gpl_syms),
3155 &mod->num_gpl_syms);
3156 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3157 mod->gpl_future_syms = section_objs(info,
3158 "__ksymtab_gpl_future",
3159 sizeof(*mod->gpl_future_syms),
3160 &mod->num_gpl_future_syms);
3161 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3162
3163#ifdef CONFIG_UNUSED_SYMBOLS
3164 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3165 sizeof(*mod->unused_syms),
3166 &mod->num_unused_syms);
3167 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3168 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3169 sizeof(*mod->unused_gpl_syms),
3170 &mod->num_unused_gpl_syms);
3171 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3172#endif
3173#ifdef CONFIG_CONSTRUCTORS
3174 mod->ctors = section_objs(info, ".ctors",
3175 sizeof(*mod->ctors), &mod->num_ctors);
3176 if (!mod->ctors)
3177 mod->ctors = section_objs(info, ".init_array",
3178 sizeof(*mod->ctors), &mod->num_ctors);
3179 else if (find_sec(info, ".init_array")) {
3180 /*
3181 * This shouldn't happen with same compiler and binutils
3182 * building all parts of the module.
3183 */
3184 pr_warn("%s: has both .ctors and .init_array.\n",
3185 mod->name);
3186 return -EINVAL;
3187 }
3188#endif
3189
3190#ifdef CONFIG_TRACEPOINTS
3191 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3192 sizeof(*mod->tracepoints_ptrs),
3193 &mod->num_tracepoints);
3194#endif
3195#ifdef CONFIG_TREE_SRCU
3196 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3197 sizeof(*mod->srcu_struct_ptrs),
3198 &mod->num_srcu_structs);
3199#endif
3200#ifdef CONFIG_BPF_EVENTS
3201 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3202 sizeof(*mod->bpf_raw_events),
3203 &mod->num_bpf_raw_events);
3204#endif
3205#ifdef CONFIG_JUMP_LABEL
3206 mod->jump_entries = section_objs(info, "__jump_table",
3207 sizeof(*mod->jump_entries),
3208 &mod->num_jump_entries);
3209#endif
3210#ifdef CONFIG_EVENT_TRACING
3211 mod->trace_events = section_objs(info, "_ftrace_events",
3212 sizeof(*mod->trace_events),
3213 &mod->num_trace_events);
3214 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3215 sizeof(*mod->trace_evals),
3216 &mod->num_trace_evals);
3217#endif
3218#ifdef CONFIG_TRACING
3219 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3220 sizeof(*mod->trace_bprintk_fmt_start),
3221 &mod->num_trace_bprintk_fmt);
3222#endif
3223#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3224 /* sechdrs[0].sh_size is always zero */
3225 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3226 sizeof(*mod->ftrace_callsites),
3227 &mod->num_ftrace_callsites);
3228#endif
3229#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3230 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3231 sizeof(*mod->ei_funcs),
3232 &mod->num_ei_funcs);
3233#endif
3234 mod->extable = section_objs(info, "__ex_table",
3235 sizeof(*mod->extable), &mod->num_exentries);
3236
3237 if (section_addr(info, "__obsparm"))
3238 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3239
3240 info->debug = section_objs(info, "__verbose",
3241 sizeof(*info->debug), &info->num_debug);
3242
3243 return 0;
3244}
3245
3246static int move_module(struct module *mod, struct load_info *info)
3247{
3248 int i;
3249 void *ptr;
3250
3251 /* Do the allocs. */
3252 ptr = module_alloc(mod->core_layout.size);
3253 /*
3254 * The pointer to this block is stored in the module structure
3255 * which is inside the block. Just mark it as not being a
3256 * leak.
3257 */
3258 kmemleak_not_leak(ptr);
3259 if (!ptr)
3260 return -ENOMEM;
3261
3262 memset(ptr, 0, mod->core_layout.size);
3263 mod->core_layout.base = ptr;
3264
3265 if (mod->init_layout.size) {
3266 ptr = module_alloc(mod->init_layout.size);
3267 /*
3268 * The pointer to this block is stored in the module structure
3269 * which is inside the block. This block doesn't need to be
3270 * scanned as it contains data and code that will be freed
3271 * after the module is initialized.
3272 */
3273 kmemleak_ignore(ptr);
3274 if (!ptr) {
3275 module_memfree(mod->core_layout.base);
3276 return -ENOMEM;
3277 }
3278 memset(ptr, 0, mod->init_layout.size);
3279 mod->init_layout.base = ptr;
3280 } else
3281 mod->init_layout.base = NULL;
3282
3283 /* Transfer each section which specifies SHF_ALLOC */
3284 pr_debug("final section addresses:\n");
3285 for (i = 0; i < info->hdr->e_shnum; i++) {
3286 void *dest;
3287 Elf_Shdr *shdr = &info->sechdrs[i];
3288
3289 if (!(shdr->sh_flags & SHF_ALLOC))
3290 continue;
3291
3292 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3293 dest = mod->init_layout.base
3294 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3295 else
3296 dest = mod->core_layout.base + shdr->sh_entsize;
3297
3298 if (shdr->sh_type != SHT_NOBITS)
3299 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3300 /* Update sh_addr to point to copy in image. */
3301 shdr->sh_addr = (unsigned long)dest;
3302 pr_debug("\t0x%lx %s\n",
3303 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3304 }
3305
3306 return 0;
3307}
3308
3309static int check_module_license_and_versions(struct module *mod)
3310{
3311 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3312
3313 /*
3314 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3315 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3316 * using GPL-only symbols it needs.
3317 */
3318 if (strcmp(mod->name, "ndiswrapper") == 0)
3319 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3320
3321 /* driverloader was caught wrongly pretending to be under GPL */
3322 if (strcmp(mod->name, "driverloader") == 0)
3323 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3324 LOCKDEP_NOW_UNRELIABLE);
3325
3326 /* lve claims to be GPL but upstream won't provide source */
3327 if (strcmp(mod->name, "lve") == 0)
3328 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3329 LOCKDEP_NOW_UNRELIABLE);
3330
3331 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3332 pr_warn("%s: module license taints kernel.\n", mod->name);
3333
3334#ifdef CONFIG_MODVERSIONS
3335 if ((mod->num_syms && !mod->crcs)
3336 || (mod->num_gpl_syms && !mod->gpl_crcs)
3337 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3338#ifdef CONFIG_UNUSED_SYMBOLS
3339 || (mod->num_unused_syms && !mod->unused_crcs)
3340 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3341#endif
3342 ) {
3343 return try_to_force_load(mod,
3344 "no versions for exported symbols");
3345 }
3346#endif
3347 return 0;
3348}
3349
3350static void flush_module_icache(const struct module *mod)
3351{
3352 mm_segment_t old_fs;
3353
3354 /* flush the icache in correct context */
3355 old_fs = get_fs();
3356 set_fs(KERNEL_DS);
3357
3358 /*
3359 * Flush the instruction cache, since we've played with text.
3360 * Do it before processing of module parameters, so the module
3361 * can provide parameter accessor functions of its own.
3362 */
3363 if (mod->init_layout.base)
3364 flush_icache_range((unsigned long)mod->init_layout.base,
3365 (unsigned long)mod->init_layout.base
3366 + mod->init_layout.size);
3367 flush_icache_range((unsigned long)mod->core_layout.base,
3368 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3369
3370 set_fs(old_fs);
3371}
3372
3373int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3374 Elf_Shdr *sechdrs,
3375 char *secstrings,
3376 struct module *mod)
3377{
3378 return 0;
3379}
3380
3381/* module_blacklist is a comma-separated list of module names */
3382static char *module_blacklist;
3383static bool blacklisted(const char *module_name)
3384{
3385 const char *p;
3386 size_t len;
3387
3388 if (!module_blacklist)
3389 return false;
3390
3391 for (p = module_blacklist; *p; p += len) {
3392 len = strcspn(p, ",");
3393 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3394 return true;
3395 if (p[len] == ',')
3396 len++;
3397 }
3398 return false;
3399}
3400core_param(module_blacklist, module_blacklist, charp, 0400);
3401
3402static struct module *layout_and_allocate(struct load_info *info, int flags)
3403{
3404 struct module *mod;
3405 unsigned int ndx;
3406 int err;
3407
3408 err = check_modinfo(info->mod, info, flags);
3409 if (err)
3410 return ERR_PTR(err);
3411
3412 /* Allow arches to frob section contents and sizes. */
3413 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3414 info->secstrings, info->mod);
3415 if (err < 0)
3416 return ERR_PTR(err);
3417
3418 /* We will do a special allocation for per-cpu sections later. */
3419 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3420
3421 /*
3422 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3423 * layout_sections() can put it in the right place.
3424 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3425 */
3426 ndx = find_sec(info, ".data..ro_after_init");
3427 if (ndx)
3428 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3429 /*
3430 * Mark the __jump_table section as ro_after_init as well: these data
3431 * structures are never modified, with the exception of entries that
3432 * refer to code in the __init section, which are annotated as such
3433 * at module load time.
3434 */
3435 ndx = find_sec(info, "__jump_table");
3436 if (ndx)
3437 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3438
3439 /* Determine total sizes, and put offsets in sh_entsize. For now
3440 this is done generically; there doesn't appear to be any
3441 special cases for the architectures. */
3442 layout_sections(info->mod, info);
3443 layout_symtab(info->mod, info);
3444
3445 /* Allocate and move to the final place */
3446 err = move_module(info->mod, info);
3447 if (err)
3448 return ERR_PTR(err);
3449
3450 /* Module has been copied to its final place now: return it. */
3451 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3452 kmemleak_load_module(mod, info);
3453 return mod;
3454}
3455
3456/* mod is no longer valid after this! */
3457static void module_deallocate(struct module *mod, struct load_info *info)
3458{
3459 percpu_modfree(mod);
3460 module_arch_freeing_init(mod);
3461 module_memfree(mod->init_layout.base);
3462 module_memfree(mod->core_layout.base);
3463}
3464
3465int __weak module_finalize(const Elf_Ehdr *hdr,
3466 const Elf_Shdr *sechdrs,
3467 struct module *me)
3468{
3469 return 0;
3470}
3471
3472static int post_relocation(struct module *mod, const struct load_info *info)
3473{
3474 /* Sort exception table now relocations are done. */
3475 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3476
3477 /* Copy relocated percpu area over. */
3478 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3479 info->sechdrs[info->index.pcpu].sh_size);
3480
3481 /* Setup kallsyms-specific fields. */
3482 add_kallsyms(mod, info);
3483
3484 /* Arch-specific module finalizing. */
3485 return module_finalize(info->hdr, info->sechdrs, mod);
3486}
3487
3488/* Is this module of this name done loading? No locks held. */
3489static bool finished_loading(const char *name)
3490{
3491 struct module *mod;
3492 bool ret;
3493
3494 /*
3495 * The module_mutex should not be a heavily contended lock;
3496 * if we get the occasional sleep here, we'll go an extra iteration
3497 * in the wait_event_interruptible(), which is harmless.
3498 */
3499 sched_annotate_sleep();
3500 mutex_lock(&module_mutex);
3501 mod = find_module_all(name, strlen(name), true);
3502 ret = !mod || mod->state == MODULE_STATE_LIVE;
3503 mutex_unlock(&module_mutex);
3504
3505 return ret;
3506}
3507
3508/* Call module constructors. */
3509static void do_mod_ctors(struct module *mod)
3510{
3511#ifdef CONFIG_CONSTRUCTORS
3512 unsigned long i;
3513
3514 for (i = 0; i < mod->num_ctors; i++)
3515 mod->ctors[i]();
3516#endif
3517}
3518
3519/* For freeing module_init on success, in case kallsyms traversing */
3520struct mod_initfree {
3521 struct llist_node node;
3522 void *module_init;
3523};
3524
3525static void do_free_init(struct work_struct *w)
3526{
3527 struct llist_node *pos, *n, *list;
3528 struct mod_initfree *initfree;
3529
3530 list = llist_del_all(&init_free_list);
3531
3532 synchronize_rcu();
3533
3534 llist_for_each_safe(pos, n, list) {
3535 initfree = container_of(pos, struct mod_initfree, node);
3536 module_memfree(initfree->module_init);
3537 kfree(initfree);
3538 }
3539}
3540
3541static int __init modules_wq_init(void)
3542{
3543 INIT_WORK(&init_free_wq, do_free_init);
3544 init_llist_head(&init_free_list);
3545 return 0;
3546}
3547module_init(modules_wq_init);
3548
3549/*
3550 * This is where the real work happens.
3551 *
3552 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3553 * helper command 'lx-symbols'.
3554 */
3555static noinline int do_init_module(struct module *mod)
3556{
3557 int ret = 0;
3558 struct mod_initfree *freeinit;
3559
3560 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3561 if (!freeinit) {
3562 ret = -ENOMEM;
3563 goto fail;
3564 }
3565 freeinit->module_init = mod->init_layout.base;
3566
3567 /*
3568 * We want to find out whether @mod uses async during init. Clear
3569 * PF_USED_ASYNC. async_schedule*() will set it.
3570 */
3571 current->flags &= ~PF_USED_ASYNC;
3572
3573 do_mod_ctors(mod);
3574 /* Start the module */
3575 if (mod->init != NULL)
3576 ret = do_one_initcall(mod->init);
3577 if (ret < 0) {
3578 goto fail_free_freeinit;
3579 }
3580 if (ret > 0) {
3581 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3582 "follow 0/-E convention\n"
3583 "%s: loading module anyway...\n",
3584 __func__, mod->name, ret, __func__);
3585 dump_stack();
3586 }
3587
3588 /* Now it's a first class citizen! */
3589 mod->state = MODULE_STATE_LIVE;
3590 blocking_notifier_call_chain(&module_notify_list,
3591 MODULE_STATE_LIVE, mod);
3592
3593 /*
3594 * We need to finish all async code before the module init sequence
3595 * is done. This has potential to deadlock. For example, a newly
3596 * detected block device can trigger request_module() of the
3597 * default iosched from async probing task. Once userland helper
3598 * reaches here, async_synchronize_full() will wait on the async
3599 * task waiting on request_module() and deadlock.
3600 *
3601 * This deadlock is avoided by perfomring async_synchronize_full()
3602 * iff module init queued any async jobs. This isn't a full
3603 * solution as it will deadlock the same if module loading from
3604 * async jobs nests more than once; however, due to the various
3605 * constraints, this hack seems to be the best option for now.
3606 * Please refer to the following thread for details.
3607 *
3608 * http://thread.gmane.org/gmane.linux.kernel/1420814
3609 */
3610 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3611 async_synchronize_full();
3612
3613 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3614 mod->init_layout.size);
3615 mutex_lock(&module_mutex);
3616 /* Drop initial reference. */
3617 module_put(mod);
3618 trim_init_extable(mod);
3619#ifdef CONFIG_KALLSYMS
3620 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3621 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3622#endif
3623 module_enable_ro(mod, true);
3624 mod_tree_remove_init(mod);
3625 module_arch_freeing_init(mod);
3626 mod->init_layout.base = NULL;
3627 mod->init_layout.size = 0;
3628 mod->init_layout.ro_size = 0;
3629 mod->init_layout.ro_after_init_size = 0;
3630 mod->init_layout.text_size = 0;
3631 /*
3632 * We want to free module_init, but be aware that kallsyms may be
3633 * walking this with preempt disabled. In all the failure paths, we
3634 * call synchronize_rcu(), but we don't want to slow down the success
3635 * path. module_memfree() cannot be called in an interrupt, so do the
3636 * work and call synchronize_rcu() in a work queue.
3637 *
3638 * Note that module_alloc() on most architectures creates W+X page
3639 * mappings which won't be cleaned up until do_free_init() runs. Any
3640 * code such as mark_rodata_ro() which depends on those mappings to
3641 * be cleaned up needs to sync with the queued work - ie
3642 * rcu_barrier()
3643 */
3644 if (llist_add(&freeinit->node, &init_free_list))
3645 schedule_work(&init_free_wq);
3646
3647 mutex_unlock(&module_mutex);
3648 wake_up_all(&module_wq);
3649
3650 return 0;
3651
3652fail_free_freeinit:
3653 kfree(freeinit);
3654fail:
3655 /* Try to protect us from buggy refcounters. */
3656 mod->state = MODULE_STATE_GOING;
3657 synchronize_rcu();
3658 module_put(mod);
3659 blocking_notifier_call_chain(&module_notify_list,
3660 MODULE_STATE_GOING, mod);
3661 klp_module_going(mod);
3662 ftrace_release_mod(mod);
3663 free_module(mod);
3664 wake_up_all(&module_wq);
3665 return ret;
3666}
3667
3668static int may_init_module(void)
3669{
3670 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3671 return -EPERM;
3672
3673 return 0;
3674}
3675
3676/*
3677 * We try to place it in the list now to make sure it's unique before
3678 * we dedicate too many resources. In particular, temporary percpu
3679 * memory exhaustion.
3680 */
3681static int add_unformed_module(struct module *mod)
3682{
3683 int err;
3684 struct module *old;
3685
3686 mod->state = MODULE_STATE_UNFORMED;
3687
3688again:
3689 mutex_lock(&module_mutex);
3690 old = find_module_all(mod->name, strlen(mod->name), true);
3691 if (old != NULL) {
3692 if (old->state != MODULE_STATE_LIVE) {
3693 /* Wait in case it fails to load. */
3694 mutex_unlock(&module_mutex);
3695 err = wait_event_interruptible(module_wq,
3696 finished_loading(mod->name));
3697 if (err)
3698 goto out_unlocked;
3699 goto again;
3700 }
3701 err = -EEXIST;
3702 goto out;
3703 }
3704 mod_update_bounds(mod);
3705 list_add_rcu(&mod->list, &modules);
3706 mod_tree_insert(mod);
3707 err = 0;
3708
3709out:
3710 mutex_unlock(&module_mutex);
3711out_unlocked:
3712 return err;
3713}
3714
3715static int complete_formation(struct module *mod, struct load_info *info)
3716{
3717 int err;
3718
3719 mutex_lock(&module_mutex);
3720
3721 /* Find duplicate symbols (must be called under lock). */
3722 err = verify_exported_symbols(mod);
3723 if (err < 0)
3724 goto out;
3725
3726 /* This relies on module_mutex for list integrity. */
3727 module_bug_finalize(info->hdr, info->sechdrs, mod);
3728
3729 module_enable_ro(mod, false);
3730 module_enable_nx(mod);
3731 module_enable_x(mod);
3732
3733 /* Mark state as coming so strong_try_module_get() ignores us,
3734 * but kallsyms etc. can see us. */
3735 mod->state = MODULE_STATE_COMING;
3736 mutex_unlock(&module_mutex);
3737
3738 return 0;
3739
3740out:
3741 mutex_unlock(&module_mutex);
3742 return err;
3743}
3744
3745static int prepare_coming_module(struct module *mod)
3746{
3747 int err;
3748
3749 ftrace_module_enable(mod);
3750 err = klp_module_coming(mod);
3751 if (err)
3752 return err;
3753
3754 blocking_notifier_call_chain(&module_notify_list,
3755 MODULE_STATE_COMING, mod);
3756 return 0;
3757}
3758
3759static int unknown_module_param_cb(char *param, char *val, const char *modname,
3760 void *arg)
3761{
3762 struct module *mod = arg;
3763 int ret;
3764
3765 if (strcmp(param, "async_probe") == 0) {
3766 mod->async_probe_requested = true;
3767 return 0;
3768 }
3769
3770 /* Check for magic 'dyndbg' arg */
3771 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3772 if (ret != 0)
3773 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3774 return 0;
3775}
3776
3777/* Allocate and load the module: note that size of section 0 is always
3778 zero, and we rely on this for optional sections. */
3779static int load_module(struct load_info *info, const char __user *uargs,
3780 int flags)
3781{
3782 struct module *mod;
3783 long err = 0;
3784 char *after_dashes;
3785
3786 err = elf_header_check(info);
3787 if (err)
3788 goto free_copy;
3789
3790 err = setup_load_info(info, flags);
3791 if (err)
3792 goto free_copy;
3793
3794 if (blacklisted(info->name)) {
3795 err = -EPERM;
3796 goto free_copy;
3797 }
3798
3799 err = module_sig_check(info, flags);
3800 if (err)
3801 goto free_copy;
3802
3803 err = rewrite_section_headers(info, flags);
3804 if (err)
3805 goto free_copy;
3806
3807 /* Check module struct version now, before we try to use module. */
3808 if (!check_modstruct_version(info, info->mod)) {
3809 err = -ENOEXEC;
3810 goto free_copy;
3811 }
3812
3813 /* Figure out module layout, and allocate all the memory. */
3814 mod = layout_and_allocate(info, flags);
3815 if (IS_ERR(mod)) {
3816 err = PTR_ERR(mod);
3817 goto free_copy;
3818 }
3819
3820 audit_log_kern_module(mod->name);
3821
3822 /* Reserve our place in the list. */
3823 err = add_unformed_module(mod);
3824 if (err)
3825 goto free_module;
3826
3827#ifdef CONFIG_MODULE_SIG
3828 mod->sig_ok = info->sig_ok;
3829 if (!mod->sig_ok) {
3830 pr_notice_once("%s: module verification failed: signature "
3831 "and/or required key missing - tainting "
3832 "kernel\n", mod->name);
3833 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3834 }
3835#endif
3836
3837 /* To avoid stressing percpu allocator, do this once we're unique. */
3838 err = percpu_modalloc(mod, info);
3839 if (err)
3840 goto unlink_mod;
3841
3842 /* Now module is in final location, initialize linked lists, etc. */
3843 err = module_unload_init(mod);
3844 if (err)
3845 goto unlink_mod;
3846
3847 init_param_lock(mod);
3848
3849 /* Now we've got everything in the final locations, we can
3850 * find optional sections. */
3851 err = find_module_sections(mod, info);
3852 if (err)
3853 goto free_unload;
3854
3855 err = check_module_license_and_versions(mod);
3856 if (err)
3857 goto free_unload;
3858
3859 /* Set up MODINFO_ATTR fields */
3860 setup_modinfo(mod, info);
3861
3862 /* Fix up syms, so that st_value is a pointer to location. */
3863 err = simplify_symbols(mod, info);
3864 if (err < 0)
3865 goto free_modinfo;
3866
3867 err = apply_relocations(mod, info);
3868 if (err < 0)
3869 goto free_modinfo;
3870
3871 err = post_relocation(mod, info);
3872 if (err < 0)
3873 goto free_modinfo;
3874
3875 flush_module_icache(mod);
3876
3877 /* Now copy in args */
3878 mod->args = strndup_user(uargs, ~0UL >> 1);
3879 if (IS_ERR(mod->args)) {
3880 err = PTR_ERR(mod->args);
3881 goto free_arch_cleanup;
3882 }
3883
3884 dynamic_debug_setup(mod, info->debug, info->num_debug);
3885
3886 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3887 ftrace_module_init(mod);
3888
3889 /* Finally it's fully formed, ready to start executing. */
3890 err = complete_formation(mod, info);
3891 if (err)
3892 goto ddebug_cleanup;
3893
3894 err = prepare_coming_module(mod);
3895 if (err)
3896 goto bug_cleanup;
3897
3898 /* Module is ready to execute: parsing args may do that. */
3899 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3900 -32768, 32767, mod,
3901 unknown_module_param_cb);
3902 if (IS_ERR(after_dashes)) {
3903 err = PTR_ERR(after_dashes);
3904 goto coming_cleanup;
3905 } else if (after_dashes) {
3906 pr_warn("%s: parameters '%s' after `--' ignored\n",
3907 mod->name, after_dashes);
3908 }
3909
3910 /* Link in to sysfs. */
3911 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3912 if (err < 0)
3913 goto coming_cleanup;
3914
3915 if (is_livepatch_module(mod)) {
3916 err = copy_module_elf(mod, info);
3917 if (err < 0)
3918 goto sysfs_cleanup;
3919 }
3920
3921 /* Get rid of temporary copy. */
3922 free_copy(info);
3923
3924 /* Done! */
3925 trace_module_load(mod);
3926
3927 return do_init_module(mod);
3928
3929 sysfs_cleanup:
3930 mod_sysfs_teardown(mod);
3931 coming_cleanup:
3932 mod->state = MODULE_STATE_GOING;
3933 destroy_params(mod->kp, mod->num_kp);
3934 blocking_notifier_call_chain(&module_notify_list,
3935 MODULE_STATE_GOING, mod);
3936 klp_module_going(mod);
3937 bug_cleanup:
3938 /* module_bug_cleanup needs module_mutex protection */
3939 mutex_lock(&module_mutex);
3940 module_bug_cleanup(mod);
3941 mutex_unlock(&module_mutex);
3942
3943 ddebug_cleanup:
3944 ftrace_release_mod(mod);
3945 dynamic_debug_remove(mod, info->debug);
3946 synchronize_rcu();
3947 kfree(mod->args);
3948 free_arch_cleanup:
3949 module_arch_cleanup(mod);
3950 free_modinfo:
3951 free_modinfo(mod);
3952 free_unload:
3953 module_unload_free(mod);
3954 unlink_mod:
3955 mutex_lock(&module_mutex);
3956 /* Unlink carefully: kallsyms could be walking list. */
3957 list_del_rcu(&mod->list);
3958 mod_tree_remove(mod);
3959 wake_up_all(&module_wq);
3960 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3961 synchronize_rcu();
3962 mutex_unlock(&module_mutex);
3963 free_module:
3964 /* Free lock-classes; relies on the preceding sync_rcu() */
3965 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3966
3967 module_deallocate(mod, info);
3968 free_copy:
3969 free_copy(info);
3970 return err;
3971}
3972
3973SYSCALL_DEFINE3(init_module, void __user *, umod,
3974 unsigned long, len, const char __user *, uargs)
3975{
3976 int err;
3977 struct load_info info = { };
3978
3979 err = may_init_module();
3980 if (err)
3981 return err;
3982
3983 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3984 umod, len, uargs);
3985
3986 err = copy_module_from_user(umod, len, &info);
3987 if (err)
3988 return err;
3989
3990 return load_module(&info, uargs, 0);
3991}
3992
3993SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3994{
3995 struct load_info info = { };
3996 loff_t size;
3997 void *hdr;
3998 int err;
3999
4000 err = may_init_module();
4001 if (err)
4002 return err;
4003
4004 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4005
4006 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4007 |MODULE_INIT_IGNORE_VERMAGIC))
4008 return -EINVAL;
4009
4010 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
4011 READING_MODULE);
4012 if (err)
4013 return err;
4014 info.hdr = hdr;
4015 info.len = size;
4016
4017 return load_module(&info, uargs, flags);
4018}
4019
4020static inline int within(unsigned long addr, void *start, unsigned long size)
4021{
4022 return ((void *)addr >= start && (void *)addr < start + size);
4023}
4024
4025#ifdef CONFIG_KALLSYMS
4026/*
4027 * This ignores the intensely annoying "mapping symbols" found
4028 * in ARM ELF files: $a, $t and $d.
4029 */
4030static inline int is_arm_mapping_symbol(const char *str)
4031{
4032 if (str[0] == '.' && str[1] == 'L')
4033 return true;
4034 return str[0] == '$' && strchr("axtd", str[1])
4035 && (str[2] == '\0' || str[2] == '.');
4036}
4037
4038static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4039{
4040 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4041}
4042
4043/*
4044 * Given a module and address, find the corresponding symbol and return its name
4045 * while providing its size and offset if needed.
4046 */
4047static const char *find_kallsyms_symbol(struct module *mod,
4048 unsigned long addr,
4049 unsigned long *size,
4050 unsigned long *offset)
4051{
4052 unsigned int i, best = 0;
4053 unsigned long nextval, bestval;
4054 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4055
4056 /* At worse, next value is at end of module */
4057 if (within_module_init(addr, mod))
4058 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4059 else
4060 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4061
4062 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4063
4064 /* Scan for closest preceding symbol, and next symbol. (ELF
4065 starts real symbols at 1). */
4066 for (i = 1; i < kallsyms->num_symtab; i++) {
4067 const Elf_Sym *sym = &kallsyms->symtab[i];
4068 unsigned long thisval = kallsyms_symbol_value(sym);
4069
4070 if (sym->st_shndx == SHN_UNDEF)
4071 continue;
4072
4073 /* We ignore unnamed symbols: they're uninformative
4074 * and inserted at a whim. */
4075 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4076 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4077 continue;
4078
4079 if (thisval <= addr && thisval > bestval) {
4080 best = i;
4081 bestval = thisval;
4082 }
4083 if (thisval > addr && thisval < nextval)
4084 nextval = thisval;
4085 }
4086
4087 if (!best)
4088 return NULL;
4089
4090 if (size)
4091 *size = nextval - bestval;
4092 if (offset)
4093 *offset = addr - bestval;
4094
4095 return kallsyms_symbol_name(kallsyms, best);
4096}
4097
4098void * __weak dereference_module_function_descriptor(struct module *mod,
4099 void *ptr)
4100{
4101 return ptr;
4102}
4103
4104/* For kallsyms to ask for address resolution. NULL means not found. Careful
4105 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4106const char *module_address_lookup(unsigned long addr,
4107 unsigned long *size,
4108 unsigned long *offset,
4109 char **modname,
4110 char *namebuf)
4111{
4112 const char *ret = NULL;
4113 struct module *mod;
4114
4115 preempt_disable();
4116 mod = __module_address(addr);
4117 if (mod) {
4118 if (modname)
4119 *modname = mod->name;
4120
4121 ret = find_kallsyms_symbol(mod, addr, size, offset);
4122 }
4123 /* Make a copy in here where it's safe */
4124 if (ret) {
4125 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4126 ret = namebuf;
4127 }
4128 preempt_enable();
4129
4130 return ret;
4131}
4132
4133int lookup_module_symbol_name(unsigned long addr, char *symname)
4134{
4135 struct module *mod;
4136
4137 preempt_disable();
4138 list_for_each_entry_rcu(mod, &modules, list) {
4139 if (mod->state == MODULE_STATE_UNFORMED)
4140 continue;
4141 if (within_module(addr, mod)) {
4142 const char *sym;
4143
4144 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4145 if (!sym)
4146 goto out;
4147
4148 strlcpy(symname, sym, KSYM_NAME_LEN);
4149 preempt_enable();
4150 return 0;
4151 }
4152 }
4153out:
4154 preempt_enable();
4155 return -ERANGE;
4156}
4157
4158int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4159 unsigned long *offset, char *modname, char *name)
4160{
4161 struct module *mod;
4162
4163 preempt_disable();
4164 list_for_each_entry_rcu(mod, &modules, list) {
4165 if (mod->state == MODULE_STATE_UNFORMED)
4166 continue;
4167 if (within_module(addr, mod)) {
4168 const char *sym;
4169
4170 sym = find_kallsyms_symbol(mod, addr, size, offset);
4171 if (!sym)
4172 goto out;
4173 if (modname)
4174 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4175 if (name)
4176 strlcpy(name, sym, KSYM_NAME_LEN);
4177 preempt_enable();
4178 return 0;
4179 }
4180 }
4181out:
4182 preempt_enable();
4183 return -ERANGE;
4184}
4185
4186int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4187 char *name, char *module_name, int *exported)
4188{
4189 struct module *mod;
4190
4191 preempt_disable();
4192 list_for_each_entry_rcu(mod, &modules, list) {
4193 struct mod_kallsyms *kallsyms;
4194
4195 if (mod->state == MODULE_STATE_UNFORMED)
4196 continue;
4197 kallsyms = rcu_dereference_sched(mod->kallsyms);
4198 if (symnum < kallsyms->num_symtab) {
4199 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4200
4201 *value = kallsyms_symbol_value(sym);
4202 *type = kallsyms->typetab[symnum];
4203 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4204 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4205 *exported = is_exported(name, *value, mod);
4206 preempt_enable();
4207 return 0;
4208 }
4209 symnum -= kallsyms->num_symtab;
4210 }
4211 preempt_enable();
4212 return -ERANGE;
4213}
4214
4215/* Given a module and name of symbol, find and return the symbol's value */
4216static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4217{
4218 unsigned int i;
4219 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4220
4221 for (i = 0; i < kallsyms->num_symtab; i++) {
4222 const Elf_Sym *sym = &kallsyms->symtab[i];
4223
4224 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4225 sym->st_shndx != SHN_UNDEF)
4226 return kallsyms_symbol_value(sym);
4227 }
4228 return 0;
4229}
4230
4231/* Look for this name: can be of form module:name. */
4232unsigned long module_kallsyms_lookup_name(const char *name)
4233{
4234 struct module *mod;
4235 char *colon;
4236 unsigned long ret = 0;
4237
4238 /* Don't lock: we're in enough trouble already. */
4239 preempt_disable();
4240 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4241 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4242 ret = find_kallsyms_symbol_value(mod, colon+1);
4243 } else {
4244 list_for_each_entry_rcu(mod, &modules, list) {
4245 if (mod->state == MODULE_STATE_UNFORMED)
4246 continue;
4247 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4248 break;
4249 }
4250 }
4251 preempt_enable();
4252 return ret;
4253}
4254
4255int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4256 struct module *, unsigned long),
4257 void *data)
4258{
4259 struct module *mod;
4260 unsigned int i;
4261 int ret;
4262
4263 module_assert_mutex();
4264
4265 list_for_each_entry(mod, &modules, list) {
4266 /* We hold module_mutex: no need for rcu_dereference_sched */
4267 struct mod_kallsyms *kallsyms = mod->kallsyms;
4268
4269 if (mod->state == MODULE_STATE_UNFORMED)
4270 continue;
4271 for (i = 0; i < kallsyms->num_symtab; i++) {
4272 const Elf_Sym *sym = &kallsyms->symtab[i];
4273
4274 if (sym->st_shndx == SHN_UNDEF)
4275 continue;
4276
4277 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4278 mod, kallsyms_symbol_value(sym));
4279 if (ret != 0)
4280 return ret;
4281 }
4282 }
4283 return 0;
4284}
4285#endif /* CONFIG_KALLSYMS */
4286
4287/* Maximum number of characters written by module_flags() */
4288#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4289
4290/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4291static char *module_flags(struct module *mod, char *buf)
4292{
4293 int bx = 0;
4294
4295 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4296 if (mod->taints ||
4297 mod->state == MODULE_STATE_GOING ||
4298 mod->state == MODULE_STATE_COMING) {
4299 buf[bx++] = '(';
4300 bx += module_flags_taint(mod, buf + bx);
4301 /* Show a - for module-is-being-unloaded */
4302 if (mod->state == MODULE_STATE_GOING)
4303 buf[bx++] = '-';
4304 /* Show a + for module-is-being-loaded */
4305 if (mod->state == MODULE_STATE_COMING)
4306 buf[bx++] = '+';
4307 buf[bx++] = ')';
4308 }
4309 buf[bx] = '\0';
4310
4311 return buf;
4312}
4313
4314#ifdef CONFIG_PROC_FS
4315/* Called by the /proc file system to return a list of modules. */
4316static void *m_start(struct seq_file *m, loff_t *pos)
4317{
4318 mutex_lock(&module_mutex);
4319 return seq_list_start(&modules, *pos);
4320}
4321
4322static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4323{
4324 return seq_list_next(p, &modules, pos);
4325}
4326
4327static void m_stop(struct seq_file *m, void *p)
4328{
4329 mutex_unlock(&module_mutex);
4330}
4331
4332static int m_show(struct seq_file *m, void *p)
4333{
4334 struct module *mod = list_entry(p, struct module, list);
4335 char buf[MODULE_FLAGS_BUF_SIZE];
4336 void *value;
4337
4338 /* We always ignore unformed modules. */
4339 if (mod->state == MODULE_STATE_UNFORMED)
4340 return 0;
4341
4342 seq_printf(m, "%s %u",
4343 mod->name, mod->init_layout.size + mod->core_layout.size);
4344 print_unload_info(m, mod);
4345
4346 /* Informative for users. */
4347 seq_printf(m, " %s",
4348 mod->state == MODULE_STATE_GOING ? "Unloading" :
4349 mod->state == MODULE_STATE_COMING ? "Loading" :
4350 "Live");
4351 /* Used by oprofile and other similar tools. */
4352 value = m->private ? NULL : mod->core_layout.base;
4353 seq_printf(m, " 0x%px", value);
4354
4355 /* Taints info */
4356 if (mod->taints)
4357 seq_printf(m, " %s", module_flags(mod, buf));
4358
4359 seq_puts(m, "\n");
4360 return 0;
4361}
4362
4363/* Format: modulename size refcount deps address
4364
4365 Where refcount is a number or -, and deps is a comma-separated list
4366 of depends or -.
4367*/
4368static const struct seq_operations modules_op = {
4369 .start = m_start,
4370 .next = m_next,
4371 .stop = m_stop,
4372 .show = m_show
4373};
4374
4375/*
4376 * This also sets the "private" pointer to non-NULL if the
4377 * kernel pointers should be hidden (so you can just test
4378 * "m->private" to see if you should keep the values private).
4379 *
4380 * We use the same logic as for /proc/kallsyms.
4381 */
4382static int modules_open(struct inode *inode, struct file *file)
4383{
4384 int err = seq_open(file, &modules_op);
4385
4386 if (!err) {
4387 struct seq_file *m = file->private_data;
4388 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4389 }
4390
4391 return err;
4392}
4393
4394static const struct file_operations proc_modules_operations = {
4395 .open = modules_open,
4396 .read = seq_read,
4397 .llseek = seq_lseek,
4398 .release = seq_release,
4399};
4400
4401static int __init proc_modules_init(void)
4402{
4403 proc_create("modules", 0, NULL, &proc_modules_operations);
4404 return 0;
4405}
4406module_init(proc_modules_init);
4407#endif
4408
4409/* Given an address, look for it in the module exception tables. */
4410const struct exception_table_entry *search_module_extables(unsigned long addr)
4411{
4412 const struct exception_table_entry *e = NULL;
4413 struct module *mod;
4414
4415 preempt_disable();
4416 mod = __module_address(addr);
4417 if (!mod)
4418 goto out;
4419
4420 if (!mod->num_exentries)
4421 goto out;
4422
4423 e = search_extable(mod->extable,
4424 mod->num_exentries,
4425 addr);
4426out:
4427 preempt_enable();
4428
4429 /*
4430 * Now, if we found one, we are running inside it now, hence
4431 * we cannot unload the module, hence no refcnt needed.
4432 */
4433 return e;
4434}
4435
4436/*
4437 * is_module_address - is this address inside a module?
4438 * @addr: the address to check.
4439 *
4440 * See is_module_text_address() if you simply want to see if the address
4441 * is code (not data).
4442 */
4443bool is_module_address(unsigned long addr)
4444{
4445 bool ret;
4446
4447 preempt_disable();
4448 ret = __module_address(addr) != NULL;
4449 preempt_enable();
4450
4451 return ret;
4452}
4453
4454/*
4455 * __module_address - get the module which contains an address.
4456 * @addr: the address.
4457 *
4458 * Must be called with preempt disabled or module mutex held so that
4459 * module doesn't get freed during this.
4460 */
4461struct module *__module_address(unsigned long addr)
4462{
4463 struct module *mod;
4464
4465 if (addr < module_addr_min || addr > module_addr_max)
4466 return NULL;
4467
4468 module_assert_mutex_or_preempt();
4469
4470 mod = mod_find(addr);
4471 if (mod) {
4472 BUG_ON(!within_module(addr, mod));
4473 if (mod->state == MODULE_STATE_UNFORMED)
4474 mod = NULL;
4475 }
4476 return mod;
4477}
4478EXPORT_SYMBOL_GPL(__module_address);
4479
4480/*
4481 * is_module_text_address - is this address inside module code?
4482 * @addr: the address to check.
4483 *
4484 * See is_module_address() if you simply want to see if the address is
4485 * anywhere in a module. See kernel_text_address() for testing if an
4486 * address corresponds to kernel or module code.
4487 */
4488bool is_module_text_address(unsigned long addr)
4489{
4490 bool ret;
4491
4492 preempt_disable();
4493 ret = __module_text_address(addr) != NULL;
4494 preempt_enable();
4495
4496 return ret;
4497}
4498
4499/*
4500 * __module_text_address - get the module whose code contains an address.
4501 * @addr: the address.
4502 *
4503 * Must be called with preempt disabled or module mutex held so that
4504 * module doesn't get freed during this.
4505 */
4506struct module *__module_text_address(unsigned long addr)
4507{
4508 struct module *mod = __module_address(addr);
4509 if (mod) {
4510 /* Make sure it's within the text section. */
4511 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4512 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4513 mod = NULL;
4514 }
4515 return mod;
4516}
4517EXPORT_SYMBOL_GPL(__module_text_address);
4518
4519/* Don't grab lock, we're oopsing. */
4520void print_modules(void)
4521{
4522 struct module *mod;
4523 char buf[MODULE_FLAGS_BUF_SIZE];
4524
4525 printk(KERN_DEFAULT "Modules linked in:");
4526 /* Most callers should already have preempt disabled, but make sure */
4527 preempt_disable();
4528 list_for_each_entry_rcu(mod, &modules, list) {
4529 if (mod->state == MODULE_STATE_UNFORMED)
4530 continue;
4531 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4532 }
4533 preempt_enable();
4534 if (last_unloaded_module[0])
4535 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4536 pr_cont("\n");
4537}
4538
4539#ifdef CONFIG_MODVERSIONS
4540/* Generate the signature for all relevant module structures here.
4541 * If these change, we don't want to try to parse the module. */
4542void module_layout(struct module *mod,
4543 struct modversion_info *ver,
4544 struct kernel_param *kp,
4545 struct kernel_symbol *ks,
4546 struct tracepoint * const *tp)
4547{
4548}
4549EXPORT_SYMBOL(module_layout);
4550#endif